3. Keihin Parts for 1977-83 NC50, NA50, NX50, NU50

April 3, 2021

== carb ID# ============  M O P E D S  ===========
6.
PA 08B-A  1977-78 Honda NC50 Express xxx    30 mph TS
6. PA 08B-B  1977-79 Honda NC50, NA50  xxxx    30 mph TS
6. PA 08C-A  1978-79 Honda NC50, NA50  xxxx   
30 mph TS
6. PA 08E-A  1980-80 Honda NC50 Express xxx    30 mph TS
6. PA 08E-B  1980-80 Honda NC50 Express xxx    30 mph TS
6. PA 08D-A  1980-80 Honda NA50 Express II x   30 mph TS
7. PA 12A-A  1981-81 Honda NCZ50 Moto Compo

7. PA 15A-A  1981-81 Honda NC50 Express xxx    30 mph TS
7. PA 16A-A  1981-81 Honda NA50 Express II  x   30 mph TS
7. PA 13B-A  1981-82 Honda NX50 Express SR x   30 mph TS
7. PA 13B-B  1982-83 Honda NC50 Express xxx     30 mph TS

7. PA 13E-A  1982-83
Honda NU50 Urban Express 30 mph TS
7. PA 25A-A  1982-83 Honda NC50AA, NU50AA    25 mph TS

 

 

 

 

 


6. Keihin
size     carb  model code  year 00 frame number range  000  model
∅12 PA08B-A or B #147 1977 NC50-1139281 to 0000000 NC50 Express (US)    30 mph
∅12 PA08B-A or B #147 1978 NC50-2000013 to 0000000 NC50 Express (US)    30 mph
∅12 PA08E-A or B #147 1979 NC50-2100011 to 0000000 NC50 Express (US)    30 mph

∅12 PA08E-A or B #147 1980 NC50-2200005 to 0000000 NC50 Express (US)    30 mph
∅12 PA08B-B    on #163 1979 AB01-5000001 to 0000000 NA50 Express II (US) 30 mph

∅12 PA08D-A    on #163 1980 AB01-5200001 to 0000000 NA50 Express II (US) 30 mph

 

1977 Honda NC50 Express

1978 Honda NC50 Express

’79 NC50 Express

 

 

 

 

 

 

 

 

 

1980 Honda NC50 Express

1980 Honda NA50 Express II

 

 

 

 

 

 

 

 

 

 

 

#0  16100-147-675
Keihin PA08B-A

#0 16100-147-676
Keihin PA08B-B

#0 16100-147-711
Keihin PA08E-A

 

 

 

 

 

 

 

 

 

#0 16100-147-712
Keihin PA08E-B

16100-163-771
Keihin PA08D-A

 

 

 

 

 

 

 

 

Flange Mount: 38 mm hole spacing. 2 x 20 (24 od) intake o-ring.

Honda Express carburetor versions, showing things that are different.

Honda Express carburetor versions

Cable choke: This carburetor has a throttle cable and a choke cable coming straight up and looping around. It has no vent hoses, vacuum hoses, or oil lines going into it. The oil injection goes into the intake manifold. The float reservoir vent is just a small tube slanting downward.

As with most Honda carburetors, fuel is never allowed to spill onto the engine or anything else. Instead an overflow tube inside the float chamber allows any overflow fuel to flow out and down the drain hose and onto the ground below the engine.  

The 1977-79 Honda NC50 and NA50 each had two carburetor versions, PA08B-A and PA08B-B. Regardless of the year, or the VIN number, they could have either version. So the customer had to look at the model number stamped into the carburetor, and tell the Honda dealer that number, to get certain parts correct. 

Oil injection hose location: The 1977-79 Honda Express had the oil hose going into the intake manifold, not the carburetor. The 1980 and later models had the oil injection hose going into the carburetor at the throttle slide area. There must have been some benefit, like maybe throttle slide lubrication.

16010-143-620
has a, c, d, e, f, g
for PA08 BA

16010-143-305
a, c, d, e, f, g, h, i 
for PA08 BA

16010-147-004
has b, c, f, g
for PA08 BB, EB

16010-147-711
has b, c, d, f, g
08 BB EB DA EA

16010-147-505
has b, c, d, f, g, i
08 BB EB DA EA

 

 

 

 

 

 

 

 

 

    quantity
o#
⇓⇓⇓⇓⇓ 
Keihin PA(a)08BA (b)08BB (c)08EA (d)08EB (e)08DA 
o# abcde price  Honda part#x  description xxx specs
10 1ooooN/A 16100-147-673 

10 1ooooN/A 16100-147-675 carburetor 77-79 NC50 PA 08B-A
10 o1oooN/A 16100-147-676 carb 77-79 NC50 NA50 PA 08B-B
10 oo1o0N/A 16100-147-711 carburetor 
1980 NC50 PA 08E-A
10 oo01o  N/A 16100-147-712 carburetor 
1980 NC50 PA 08E-B
10 oooo1N/A 16100-163-771 carburetor  1980 NA50 PA 08D-A

o1 10ooo $21 16010-143-620 gasket solo-set   1a o c d e f g
o1 10ooo $23 16010-143-305 gasket multi-set  1a o c d e f g h i

o
1 01o1o $23 16010-147-004 gasket solo-set   oo b c o o f g
o1 o1111 $23 16010-147-711 gasket solo-set   oo b c d o f g
o1 o1111 $21 16010-147-505 gasket multi-set oo b c d o f g o i

1a 100o0 $$3 00000-000-000 top rubber washer 10 x 18 x 1
1b o1111 $$8 00000-000-000 top rubber washer 13 x 16.5 x 1
1c 11111 $$2 00000-000-000 intake o-ring 2 x 20 (24 od) 
1d 1o1o1 0$2 16176-551-004 jet or screw o-ring 1 x 3 (5 od)
1e 1o0oo $10 16197-063-004 jet support pad disk Ø7.5 x 1.8
1f 11111 $15 00000-000-000 float bowl gasket  Ø1.5 NC50-type
1g 11111 $$2 00000-000-000 drain plug o-ring 1.5 x 4 (7 od)
o2 1oo1o $21 16011-881-741 float needle valve  stirrup
o2 o11o1 $22 16155-883-005 float needle valve regular
o3 1o1o0  N/A 16012-147-004 needle set 3a 3b 3c 3d 08BA EA
o3 ooooo $22 16012-130-640 needle set 3a 3b 3c 3d PA 03A-A
o3 ooooo $22 16012-165-014 needle set 3a 3b 3c 3d PA 03B-A

o3 o1o11 $15 16012-147-014 needle set 3a 3b 3c 08BB EB DA
3a 11111 0$5 16156-044-004 jet needle w-clip
3b 11111 0$2 16157-044-004 jet needle e-clip 1.5 for Ø2.0 needle
3c 11111 $10 00000-000-000 jet needle Ø2.0 D348 thick 08B-A,
3c 11111 $10 00000-000-000 PA 08B-B, 03A-A, 00A, 01A

3c ooooo $10 00000-000-000 jet needle Ø2.0 D117 thin 03B-A,
3c ooooo $10 00000-000-000 PA 03C-A, 03D-A, 03H-B, 03M-A, etc
3d 1o1oo  N/A 00000-000-000 needle jet (emulsion tube) 08BA 08EA
3d o1o11  N/A 00000-000-000 needle jet & jet fixed 08BB 08EB 08DA

3d ooooo $10 00000-000-000 needle jet (emulsion tube) PA 03A-A
3d ooooo $10 00000-000-000 needle jet (emulsion tube) PA 03B-A
o
4 1oo1o  N/A 16013-143-620
o4 1oo1o  N/A 16013-099-691 float set 4a oo 4c 4d black stirrup
o4 o11o1 $28 16013-147-004 float set oo 4b 4c 4d white regular
4a 1oo1o  N/A 00000-000-000 float bare, solid black foam stirrup
4b o11o1 $21 00000-000-000 float bare hollow white plastic regular
4c 11111 $$4 00000-000-000 hinge pin substitute Ø2 x 18.5
4d 11111 $$3 0-93600-04006 hinge screw M4x6 sunk phillips

1977-79 NC50 idle adjustment screws
7a idle speed screw, tighter is faster
7c idle air mix screw, tighter is richer

o5 1oooo $23 16014-143-620 top set substitute 5a 1a M20-1.0
o5 o1111 $22 16014-147-004 top set substitute 5a 1b M18-1.0
o6 1ooooN/A 16015-147-004 chamber set A 6a oo 6c 1e 1f 1g for jet pad
o6 o1111  N/A 16015-147-014 chamber set B oo 6b 6c oo 1f 1g for no pad
6a 1oo0oN/A 16015-147-004 float bowl A shallow with pad holder
6b o1111  N/A 16015-147-014 float bowl B shallow, no jet pad holder
6c 11111 $16 00000-000-000 
float drain screw M6x20 special
o7 11o1o $15 16016-143-620 screw set 7a b c d idle air
o
7 oo101  N/A 16016-147-711 screw set 7a b o d e f g idle fuel

7a 11111 $$4 00000-000-000 idle speed screw M4x19 special
7b 11111 $$2 00000-000-000 idle speed screw spring Ø5.6 x 10
7c 11o1o $$6 00000-000-000 idle air screw M6-0.75 thick tip
7d 11111 $$7 00000-000-000 idle air or fuel spring Ø4.8 x 9
7e oo1o1  N/A 00000-000-000 idle fuel screw M6-0.75 thin tip
7f  oo1o1 $$3 00000-000-000 idle fuel screw washer 3.1 x 5.0 x 0.5
7g oo1o1 0$2 16176-551-004 idle fuel screw o-ring 1 x 3 (5 od)

1980-83 NC50 idle adjustment screws
7a idle speed screw, tighter is faster 
7e idle fuel mix screw, tighter is leaner

o8 11111 $38 16022-143-620 valve set 8a, 8b
8a 11111 $22 00000-000-000 throttle slide Ø13 #15A
8b 11111 $12 00000-000-000 throttle spring original Ø9.5 x 42
8b
11111 $$7 00000-000-000 throttle spring substitute shorter, stiffer
o9 11111 $25 16046-147-004 choke set substitute 9a 9b 9c
9a 11111 $10 00000-000-000 choke top substitute plastic M12-1.0
9a 11111 $15 00000-000-000 choke top substitute metal M12-1.0
9b 11111 $$4 00000-000-000 choke spring substitute
9c 11111 $12 00000-000-000 choke slide substitute
11 11111 $2.00 16118-166-004 rubber boot substitute Dellorto
12 22222 $1.00   93500-04012 bowl screw M4x12 pan phillips
13 22222 $0.20   94111-04000 lock washer M4 split
14 11111 $1.00 95001 – 35003 hose substitute 1/8 x ¼ 3.1 x 6.3

1977-80 NC50 cable choke top substitute

15 11111  N/A 95002 – 02070 drain hose clamp B7 (for 7 not 6.3)
16 10o0o  
N/A 99201.081.0780 push-in jet 78 08BA

16 10o0o $23 substitute jet, #70 drilled to 78 08BA
16 01111 N/A fixed needle jet & jet pressed in 08BB EA EB DA
this jet is 0.78mm 0.0307″, cleaned with a #69 drill 0.0292″     

 

Float: The white float with non-stirrip needle for PA08B-B and the black float with stirrup type needle for PA08B-A do not interchange. The white float is too “tight” on the PA08B-A. Something restricts its movement. The black float is too “loose” on the PA08B-B. It moves a lot before moving the needle.

Main Jet: On PA08BB, EA, EB and DA versions the main jet is a tamper-proof tight press-fit type, in the center. The jet cannot be removed, and cannot be replaced. It is 0.78 mm – 0.0307″, and can be cleaned perfectly with a #69 drill 0.0292″.    

On a PA08BA the main jet presses or slides in and out, and is supported by a rubber disk. If the disk is missing, the jet can slide downward, allowing fuel to get past the jet o-ring, causing a rich fuel mixture.

Idle Hole Cleaning: Near the engine side of the carb body is a brass tube that dips down into the liquid gasoline. That tube, about 1.5 mm (0.060″) inner diameter and 20mm long, leads to the idle or pilot jet, which is about 0.30 mm (0.012″). The idle jet gets clogged from sitting, then the engine will run but won’t idle. Nothing but a very thin (0.010″) steel guitar string will clean it out. See below about jet drills and cleaning tiny jets. Ultrasonic parts cleaners, carb spray, carb dip, and compressed air are not usually effective. Another way to clean out the idle jet is to 1) place a drill bit that fills the hole (so it does not get crushed), 2) clamp it with a small vise grips, 3) rotate back and forth while pulling, 4) when it comes out, the actual hole is easy to see and clean, 5) press it back in the same way it came out.

Strong solvent is needed to dissolve varnish or tar residue left from years of sitting. Carburetor spray, parts dip, or acetone all help clean out the tar, sometimes with a lot of scraping, brushing or rubbing. Always remember to remove all rubber things first, to not let the rubber touch the solvent. Strong solvents will swell soft rubber, deforming it. Never soak the whole carburetor in strong solvent. In this way, Shaun (at Royal Cyclery and later at Myrons Mopeds) has successfully cleaned out over 100 Honda Express carburetors, without ever replacing any of the rubber gaskets. Part of the reason was they were only sold at Honda dealers, but nonetheless, they are not needed in a normal service or clean-out.

Keihin PA08C-A: This is approximately for a 1979-80 NC50, or maybe NA50. It is identical to a PA08B-B. It has the same white float, non-stirrup float needle, fixed jet, 18mm top threads, and same gaskets. The idle mixture screw type is unknown. No photo available. 

 


7. Keihin
size  carb  model code  years       models
∅12 PA12A-A on #GC6 1981-81 Honda NCZ50 Moto Compo
∅12 PA15A-A on #190 1981-81 Honda NC50 Express (US) xxxxx xxxx 30 mph
∅12 PA16A-A on #193 1981-81 Honda NA50 Express II (US) xxxx xxx  30 mph

∅12 PA13B-A on #187 1981-82 Honda NX50 Express SR (US) xxxx xx  30 mph
∅12 PA13B-B on #GA6 1982-83 Honda NC50 Express (US) xxxxx xoxx 30 mph

∅12 PA13E-A on #GC1 1982-83 Honda NU50 Urban Express (US) xxxx 30 mph

∅12 PA13E-A on #GC1 1982-83 Honda NU50M Urb. Expr. Deluxe (US)  30 mph
∅11 PA25A-A on #GA6 1982-83 Honda NC50AA Express (Iowa) xxxxxx25 mph
∅11 PA?????   on #GC1 1982-83 Honda NU50AA Urban Express (Iowa)   25 mph
∅10? PA25A-A on#GC1 1982-83 Honda NU50MA Urb. Ex. Deluxe (Iowa) 25 mph

 

1981 NC50 Express

1981 NA50 Express II

1981 NX50 Express SR

1982 NU50 Urban Express

 

 

 

 

 

 

 

 

#0   16100-GC6-003  Keihin PA12A-A 

16010-187-003 gasket set

 

 

 

 

 

 

 

 

#0  16100-190-672
Keihin PA15A-A

#0  16100-193-672
Keihin PA16A-A

#0  16100-187-673
Keihin PA13B-A

 

 

 

 

 

 

 

 

#0 16100-GA6-671
Keihin PA13B-B

#0 16100-???-???
Keihin PA25A-A

#0  16100-GC1-671
Keihin PA13E-A

 

 

 

 

 

 

 

 

Flange Mount: 38 mm hole spacing, 2 x 20 (24 od) o-ring on NC50, NA50 (PA15A-A, PA16A-A, PA13B-B)
Flange Mount: 32 mm stud spacing, 2 x 18 (22 od) o-ring on NX50, NU50, NU50M (PA13B-A, PA13E-A)
Flange Mount: 36 mm hole spacing, 2 x 20 (24 od) o-ring on NC50I, (PA25A-A)

Vacuum-operated automatic choke: These carburetors feature a screw-in main jet, and a built-in vacuum-operated (not electric) automatic choke. When the temperature switch on the head is cold, it allows the engine vacuum to raise the choke plunger up, which opens a new fuel passage, to enrich the mixture during cold starting. As the engine warms up, it closes the vacuum, allowing the thin spring to pull it back down, for normal running. The more precise term for this is “automatic vacuum operated cold start fuel mixture enrichment device”. The 1981-83 automatic choke device itself is not replaceable.

The vacuum source hose has a check ball valve that only allows air flow into the carburetor venturi, and not back out. It needs this even though there is reed valve, because there is still some residual reverse flow caused by the forward and reverse motion of the piston.

The vacuum choke that came out in 1981 did not last long. After 1983, 50cc on-road Honda’s had electric chokes, because they were electric-start scooters with 12 volt batteries. 

Identical twins: The PA16A-A looks identical to the PA15A-A. It is on the 1981 Honda NA50 Express II, the final year of that USA-only model. They both have 38 mm flange hole spacing, #75 screw-in jet, 20 mm intake o-ring and the non-stirrup type B float needle. The only difference is the top cable curved pipe. On a PA15A-A it is permanently attached to the screw-on top cap with a swivel joint, while on a PA16A-A the curved cable pipe is detachable.

Intake studs: After 1981 these carbs had studs instead of threaded holes in the mounting flange, except for PA25A-A. PA13B-A and PA13E-A studs are spaced 32 mm with a 18mm intake o-ring. PA13B-B studs are spaced 38 mm, with a intake o-ring 20 mm. 

Iowa carb: The PA25A-A is like a PA13B-A, with M18-1.0 top cap threads, vacuum-operated automatic choke, choke jet in float bowl, tall 2.5 x 1.5 float bowl gasket, intake o-ring 20 mm, non-stirrup type float and float needle, screw-in main jet size 75. The only noticeable difference is the absence of studs.

Iowa cylinder: The exhaust port is restricted. Here left is 49-state, right is Iowa.

#1 16010-190-004
for 15A 16A 13BB 25A

#1 16010-187-003
for PA 13BA 13EA

#1  16010-GF8-305 for
for PA 13BA 13EA

 

 

 

 

 

 

 

 

 

PA 15AA 16AA 13BA 13BB 13EA

      quantity
o#
⇓⇓⇓⇓⇓⇓ 
PA (a)15AA (b)16AA (c)13BA (d)13BB (e)25AA (f)13EA
o# abcdef price  Honda part#x  description xxx specs
00 1o0000  N/A 16100-190-672 carburetor ’81-81 NC50 PA15A-A
00 o10000  N/A 16100-193-672 carburetor ’81-81 NA50 PA16A-A
00 o01000  N/A 16100-187-673
carburetor ’81-82 NX50 PA13B-A
00 o00100  N/A 16100-GA6-671 carburetor ’82-83 NC50 PA13B-B
00 o0001N/A 16100-
GA6-671 carburetor ’82-83 NC50AA PA25A-A
00 o0000
N/A 16100-GC1-671
carburetor ’82-83 NU50 PA13E-A
01 001
001 $24 16010-187-003 gasket solo-set   1b o d g h k
01 110110 $24 16010-190-004 gasket solo-set   1b c d g o k
01 001001 $25 16010-GF8-305 gasket multi-set 1b o d g h k t u

1b 111111 $$8 00000-000-000 top rubber washer 13 x 16.5 x 1
1c 110110 $$2 00000-000-000 intake o-ring 2 x 20 (24 od) 
1d 111111 0$2 16176-551-004 idle fuel screw o-ring 1 x 3 (5 od)
1g 111111 $$2 00000-000-000 drain plug o-ring 1.5 x 4 (7 od)

1h 001001 $$2 00000-000-000 intake o-ring 2 x 18 (22 od)
1k 111111 $22 00000-000-000 float bowl gasket 2.5 tall by 1.5 wide
02 0010?0  N/A 16012-187-671 needle set 2a 2b

02 1100?0  N/A 16012-193-671 needle set 2a 2b 2c 2d
02 0001?1  N/A 16012-GA6-671 needle set 2a 2b 2c oo 2e

02 0000?1  N/A 16012-GC1-671 needle set 2a 2b 2c oo 2f

2a 111111 0$5 16156-044-004 jet needle w-clip
2b 111111 0$2 16157-044-004 jet needle e-clip for 1.5 clip groove
03 111111 $28 16013-147-004 float set white 3a 3b 3c
3a 111111 $21 00000-000-000 float bare white plastic regular
3b 111111 $$4 00000-000-000 hinge pin substitute Ø2 x 18.5
3c 111111 $$3 0-93600-04006 hinge screw M4x6 sunk phillips
04 1o0000  N/A 16014-190-014 top set NC50 fixed cable pipe M18-1.0
04 o10000 $24 16014-147-014 top set NA50 detachable pipe M18-1.0
04 o01110  N/A 16014-187-013 top set NX50, 82-83 NC50 M18-1.0

04 o00001  N/A 16014-GB2-003
04 o00001  N/A 16014-GB0-831 

04 o00001  N/A 16014-098-980 top set NU50 fixed cable pipe M18-1.0

05 110000  N/A 16015-191-034 chamber set deep bowl with choke jet
05 001000  N/A 16015-187-671 chamber set deep bowl with choke jet
05 0001?0  N/A 16015-GA6-671 chamber set deep bowl with choke jet

05 0000
?N/A 16015-187-043 chamber set deep bowl with choke jet
06 000111 $32 16016-191-004 idle fuel screw set
06 111000 $32 16016-187-003 idle fuel screw set

6e 111000  N/A 00000-000-000 idle fuel mixture screw M6-0.75 special
6b 111111 $$7 00000-000-000 idle fuel mix screw spring Ø5 x 9
6f  111111 $$3 00000-000-000 idle fuel mix screw washer 3.1×5.0x0.5
07 111111 $0016028-187-003
07 111111 $15 16028-GC8-004 idle speed screw and spring 7a 7b

7a 111111 $$4 00000-000-000 idle speed screw M4x19 special
7b 111111 $$2 00000-000-000 idle speed screw spring Ø5.5×10
08 1100?0 $38 16022-143-620 throttle slide & spring
08 0010?1  N/A 16022-187-731 throttle slide & spring
08 0001?1 
N/A 16022-191-004 throttle slide & spring
8a 110000 $22 00000-000-000 throttle slide Ø13 #15A
8b 110000 $12 00000-000-000 throttle slide spring Ø9.5 x 42

NC50 idle fuel screw
top: original 
bottom: replacement

10 100000  N/A 16118-086-004
10 100000  N/A 16118-166-004 cable rubber boot
10 101110  N/A 16118-187-003 cable rubber boot
10 00000N/A 16118-GB4-003 cable rubber boot

11 111111 $22 16155-883-005 float needle valve KL 18-4608
12 110110  N/A 16199-435-771 overflow hose 3.0 x 6.5
12 00100N/A 16199-187-003 
12 00100N/A 16198-HC0-405 overflow hose 3.0 x 6.5
13 001000  N/A 16608-187-000 control hose with check ball 5 x 10

13 110000  N/A 16608-193-670 control hose with check ball 5 x 10
13 000110  N/A 16608-GA6-670 control hose with check ball 5 x 8

13 00000N/A 16608-GC1-000 control hose with check ball 5 x 8

14 222222 0$1 93892-04012-08 screw & washer M4x12 pan phillips
15 111111  N/A 95002 – 02070   hose clamp B7 vacuum source hose
16 111000  N/A 95002 – 02100   hose clamp B10 for control hose
16 000111  N/A 95002 – 02080   hose clamp B8 for control hose

17 111111  N/A 95002 – 02650   hose clamp B6.5 for overflow hose
18 111111  N/A
 95005 – 35001   vacuum (source) hose 3.5 x 7 x 130
19 oo0010 $$7 99101-187-0700 screw-in jet #70 M6-0.75 PAMOA PA25A ? 78-80 Indian, 82-83 NC50I
19 110100 0$7 99101-187-0750 screw-in jet #75 M6-0.75 PA15A 16A 13BB 81-83 NC50, 81 NA50
19 oo1000 0$7 99101-187-0780 screw-in jet #78 M6-0.75 PA13BA 81-82 NX50
19 oo0001 0$7 
99101-187-0850 screw-in jet #85 M6-0.75 PA13EA 82-83 NU50

 

 

Float Valve Seat: On these carburetors the float seat (the cup that the float needle valve slides in) is carved into the actual carburetor body, and is not replaceable. Polish it with a spinning Q-tip and polish, such as Turtle Wax. 

Choke jet: On all of these NC50-type carbs, both shallow and deep-float-bowl versions, there is a choke jet, pressed into a corner of the float bowl. When it gets clogged the engine will only start easily when it is warm.

Verify all jets and fuel or air passageways are open, using wires and or visually with carb spray (wear goggles).

Cable Differences: You can tell what year range a Honda Express is from a distance. A 1977 to 1980 has two cables, a throttle and a choke cable coming straight up from the carburetor.  A 1981 has just a throttle cable coming straight up, but also a vacuum hose for the choke and a float vent hose.  A 1982 to 1983 has a black plastic curved elbow on top, that redirects the throttle cable forward and down, a vacuum hose for the choke, and a vent hose. A 1982-83 also has a different frame, a low headlight, and a two speed transmission.

The Honda Express throttle cable curves rearward and loops downward to get below the carburetor, and then goes forward into the frame tube. The loop design adds friction, but it makes a good clean step-thru frame without any cables or wires hanging out.  

1982-83 NC50 hoses

Comparison of PA MOA-A, PA 08B-B, PA 08B-A, and PA 15A-A

 

 

 

 

 

 

 

 

 

Keihin idle mixture screw channels
Left PA08B-B with idle air screw
Right PA15A-A with idle fuel screw

 

 

You can tell the difference between a carb with an idle air mixture screw, and a carb with an idle fuel mixture screw, by the shape of the casting at the top of the float chamber.

 

 

 

 

 

 

 

 


Mikuni Carburetors

October 19, 2016

Contents:
1 a. for 1979-81 Yamaha QT50, VM12-SC-3L5 round float
   b. for 1982-87 Yamaha QT50, VM12-SC-4L4 round float
   c. for 1983-02 Yamaha PW50, VM12-SC-4X4 round float
   d. for 2003-06 Yamaha PW50, VM12-SC-5PG round float
2 a. for 1983-90 Trac (Daelim),  VM13-SC-R4  round float
   b. for 1980-84 Indian AMI50,  VM10-SC-H9  round float
3.    for 1976-80 Angel (TYM),  VM10-24 square twin float 
4.    Other Carbs like Mikuni
5.    Mikuni Jets
6.    Info
7.    Tillotson Carburetor on 1978 Indian AMI-50

These are the baby Mikuni’s, the smallest of the small, 10 to 13mm for limited 50cc engines. See Info below.  


1. Mikuni VM12SC on Yamaha QT50 and PW50

This is a 12mm carburetor (12mm venturi diameter) with a 18mm clamp diameter.

It is not like any common Mikuni for a limited 50cc, like a moped or a kids off road. Apparently, Mikuni made carbs according to to each big manufacturer’s design. So Kawasaki KDX50, Suzuki JR50 have baby Mikuni carbs but with different designs than Yamaha PW50 and QT50. 

VM12SC versions: The first version was 3L5 on 1979-81 QT50. It had an idle air screw just to the left of the idle speed screw. After 1981, on versions 4L4, 4X4, 5PG the air screw was to the right of the idle speed screw. The off road 4X4 and 5PG versions were mostly the same except the cables exited at 90 degrees, with metal curved pipes, instead of straight up.

1979-81 Yamaha QT50
3L5-00 with #75 jet
3L5-01 with #70 jet

1982-87 Yamaha QT50
4L4-00 with #70 jet

1983-02 Yamaha PW50 4X4-00
2003-06 Yamaha PW50 5PG-00

 

 

 

 

 

 

 

 

 

 

Mikuni 3L5, 4L4, 4X4, 5PG

Combined Parts List  A= 3L5 on ’79-81 QT50,  B= 4L4 on ’82-87 QT50
Combined Parts List  C= 4X4 on ’83-02 PW50, D= 5PG on ’03-06 PW50
#  quantities
01 A B C D   Yamaha # xxx price    description
01 1 0 0 0  3L5-14101-01    N/A  carburetor 70 jet 79-81 QT50
01 0 1 0 0  4L4-14101-00    N/A  carburetor 70 jet 82-87 QT50
01 0 0 1 0  4X4-14101-00    N/A  carburetor 70 jet 83-02 PW50
01 0 0 0 1  5PG-14101-00    N/A  carburetor 70 jet 03-06 PW50
02 1 1 1 1  3L5-14181-07    N/A  float bowl
03 1 1 1 1  3L5-14184-00    N/A  float bowl gasket
04 1 1 1 1  620-14231-14 $8.00 main jet 70 M5-0.75 large round
05 1 1 0 0  3L7-14141-10    N/A  needle jet E0 Ø2.05
05 0 0 1 1  3L7-14141-12    N/A  needle jet
06 1 1 1 1  3L5-14142-40 $0.00 idle jet 40 M4-0.7 thread
07 4 4 4 4  98580-04014  $0.70 float bowl screw M4 x 14 phillips
08 1 1 1 1  3L5-14198 00    N/A  top gasket
09 1 1 0 0  3L5-14158-00    N/A  carb top cap
10 2 2 0 0  12G-14106-00 $5.00 cable adjuster-stop M6-0.75 
11 2 2 1 1  802-14161-00 $2.50 adjuster lock nut M6-0.75 x 3 hex9
12 2 2 0 0  8A7-14169-10 $2.00 cable rubber cap
13 1 1 1 1  3L6-14185-01    N/A  float (not Trac, 90 deg different)
14 1 1 1 1  3L5-14190-00  N/A    float needle = Trac 10206
15 1 1 1 1  603-14186-00 $4.00 hinge pin Ø2 x 16
16 1 1 0 0  3L5-14112-25    N/A  throttle slide
16 0 0 1 1  3L5-14112-40    N/A  throttle slide
17 1 1 1 1  3L5-14137-00 $5.00 spring stop “M” clip
18 1 1 1 1  3L6-14116-06    N/A   jet needle 3X1  Ø2.0 Ø1.36 x 30.7
18 1 1 1 1  36R-1490J-06    N/A   jet needle set 17, 18, 20  3X1
19 1 1 1 1  174-14131-01 $9.00 throttle spring Ø10.5 x 52
20 1 1 1 1  127-14137-00 $2.00 jet needle clip    Ø2.0
21 1 1 1 1  3L6-14133-00 $0.00 idle speed screw spring
22 1 1 1 1  36R-14103-00 $0.00 idle speed adjust screw
23 1 1 1 1  58E-14171-00 $0.00 choke plunger
24 1 1 1 1  127-14135-00 $0.00 choke spring
25 1 1 1 1  98580-05012  $0.60 top cover screw M5 x 12 phillips
26 1 1 1 1  92990-05100  $0.25 top screw washer M5 spring type
27 1 0 0 0  3L5-14123-01 $0.00 early idle air mixture screw (’79-81)
28 1 0 0 0  3L5-14962-00 $0.00 early idle air screw washer (81 only?)
29 1 1 1 1  95380-05600  $1.50 clamp nut M5 x 5 hex9
30 1 1 1 1  98517-05030  $0.70 clamp bolt M5 x 30 pan phillips
31 1 1 1 1  90445-05N13  $0.00 drain hose 200mm
32 2 2 2 2  3F7-14134-00  $5.00 air and drain screw spring Ø4.8 x 10
33 1 2 2 2  36R-14104-00  $6.00 air and drain screw M6-0.75×20
34 1 1 1 1  1M3-14997-00   N/A  clamp seal Ø23
35 1 1 1 1  1V3-14271-00   N/A   clamp sleeve Ø18 x Ø23 slotted
36 0 0 1 1 not sold separate
N/A  top cover with curved pipes
39 0 0 2 2  17L-14106-00 $2.50 cable adjuster nut M6-0.75×3 hex9
40 0 0 2 2  17L-14106-00 $6.00 cable adjuster
41 0 0 2 2  180-14169-00 $0.00 cable rubber cap

41 0 0 2 2  WPS-70-1028  $3.00 rubber cap similar, newer style

.

.

.


2. Mikuni H9-10 on Indian, R4-13 on Trac (Daelim)

H9 is a 10mm carb with a 18mm clamp diameter.
R4 is a 13mm carb with a 20mm clamp diameter.

They look almost the same, and share many parts in common.

1979-84 Indian mopeds, some

1984-90 Trac mopeds with Daelim engine

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Mikuni H9-10 and R4-13

Combined Parts List         L = Trac Liberty, Escot, Image  O = Trac Olympic
0 quantities Trac#  new xx   C = Trac Clipper, Hawk, Sprint   I = Indian AMI50 

0 quantities Trac#  new  
01  L O C I  Trac#  Trac# xxIndian# xx price   description   
00  1 1 0 0  12201 13201 E000-00-00   N/A    carburetor Trac Liberty R4-13
01  0 0 1 0  00000 13202 E000-00-00   N/A    carburetor Trac Clipper R4-13D
01  0 0 0 1  00000 00000 E210-30-50   N/A    carburetor Indian AMI50 H9-10   
01  1 1 1 0  12201 13201 E000-00-00   $75   carburetor body bare Trac
01  0 0 0 1  00000 00000 E210-30-50   N/A  carburetor body bare Indian
02  1 1 0 1  12211 13215 E237-70-50   N/A    needle jet E8 Ø2.05
02  0 0 1 0  00000 13216 E000-00-00   N/A    needle jet D8 Ø2.10
03  1 1 1 1  10206 00000 E238-80-50   N/A    float needle Yamaha 3L5-14190-01
04  1 1 1 0  10201 00000 E000-00-00  $0.00 idle jet 40, thread M4-0.7
04  0 0 0 1  00000 00000 no number     N/A   idle jet not-replaceable, tight press
05  0 0 0 0  00000 00000 E236-00-50  --N/A- main jet 60, M5-0.75 small round
05  0 0 0 1  00000 00000 E236-25-50  $8.00 main jet 62.5  use Dellorto  #60
05  1 1 0 0  12205 13206 E000-00-00  --N/A- main jet 65 use Dellorto 1486 #62

05  0 0 1 0  00000 13207 E000-00-00  --N/A- main jet 70 use Dellorto 1486 #68
06  1 1 1 1  12218 13223 E238-10-50    N/A   float white-clear plastic (not QT50)
07  1 1 1 1  10207 00000 E238-07-50  $4.00 float hinge pin Ø2 x 16
08  1 1 1 1  12203 13204 E238-00-50    N/A   float bowl gasket
09  1 1 1 0  12204 13205 E000-00-00    N/A   float bowl no vent
09  0 0 0 1  00000 00000 E238-30-50    N/A   float bowl w/vent
10  2 2 2 2  10202 00000 E237-06-50  $0.70 float bowl screw M4 x 14 phillips
11  1 1 1 1  12217 13222 E238-12-50  $0.60 top cover screw M4 x 25 phillips
12  2 2 2 2  10203 00000 E237-01-50  $N/A   rubber cap original short
12a2 2 2 2 10203a00000 E237-01-50a $3.00 rubber cap substitute 70-10228c
14  0 0 0 1  00000 00000 E237-02-50    N/A   top cover, smooth cable holes
15  1 1 1 1  12213 13218 E237-04-50    N/A   top gasket
16  1 1 1 1  10204 00000 E238-16-50 $9.00 throttle spring Ø10.5 x 52 
17  1 1 1 1  12207 13209 E237-11-50  $0.00 spring plate (can use “M” clip)
18  1 0 0 0  12210 00000 E000-00-00  $0.00 jet needle 3J2-3 Ø2.0 
18  0 1 0 0  00000 13213 E000-00-00  $0.00 jet needle 3X6-4 Ø2.0
18  0 0 1 0  00000 13214 E000-00-00  $0.00 jet needle 3T6-4 Ø2.0 Ø1.45 x 31.9
18  0 0 0 1  00000 00000 E237-08-50 $0.00  jet needle 3G1-6 Ø2.0 Ø1.40 x 34.4 

19  1 1 1 1  12206 13208 E237-12-50  $2.00 needle clip    Ø2.0
20  1 1 0 1  12216 00000 E238-14-50    N/A   throttle slide Ø14 x 20, says 2.0
20  0 0 1 0  00000 13221 E000-00-00    N/A   throttle slide Ø14 x 20, says 4.0

21  1 1 1 1  12213 13218 E237-04-50  $1.50 clamp nut M5 x 4 hex9
22  1 1 1 1  12220 13225 E238-02-50  $0.00 choke spring Ø6 x 19
23  1 1 1 1  12219 13224 E238-06-50  $0.00 choke plunger Ø8 x 20
24  1 1 1 1  12212 13217 E237-05-50  $0.60 clamp screw M5 x 25 phillips
25  1 1 1 1  12208 13210 E237-10-50  $9.00 idle spd screw M6-0.75×17 short tip
26  2 2 2 2  12209 13211 E237-09-50  $5.00 idle screw spring Ø4.8 x 10 (used 9)
27  1 1 1 1  10205 00000 E238-18-50  $6.00 idle air screw M6-0.75×20, long tip
28  2 2 2 0  10208 00000 E000-00-00  $N/A   cable rubber boot original
28a2 2 2 0  10208a 0000 E000-0 0-00  $2.00 cable rubber boot substitute 1476-06
29  2 2 2 0  10209 00000 E000-00-00  $6.00 cable adjuster-stop M6-0.75×16 hex7
30  1 1 1 0  12215 13220 E000-00-00   $19   top cover, threaded cable holes
31  4 4 4 0  10210 00000 E000-00-00  $3.00 adjuster lock nut M6-0.75 x 2 hex7
32  2 2 2 0  12222 13227 E000-00-00  $0.00 cable curved pipe M6-0.75
33  0 0 0 1  00000 00000 E000-00-00    N/A  clamp sleeve Ø18 x Ø23
33  1 1 1 0  00000 00000 E000-00-00    N/A  clamp sleeve Ø20 x Ø23

Mikuni cable rubbers

Indian Mikuni idle hole before and after drilling

 

 

 

 

 

 

 

 

Indian Mikuni carb service

The idle hole is often blocked. There are three spray holes, the main and mid-range under the throttle slide, and the smaller idle hole downstream of the throttle slide. When the bike is idling the slide is down and only the idle hole is active. A small slit of air under the slide blows over it, creating the suction and breaking up the liquid gasoline into small droplets. The drill size is tiny, a #76 which is 0.020 inch. The drill is held in a pin vise. The pin vise goes into the drill chuck. After about 2mm of depth there is a empty chamber behind the hole. That chamber leads to the idle jet which is at the top of a vertical tunnel-tube made into the zinc casting. The idle jet can be cleaned separately from below. It is smaller, like maybe 0.010 inch. That is smaller than the smallest drill #80 in a numbered set.

Carb spray is used to tell if the idle hole or idle jet is clogged. When sprayed up from the vertical idle tunnel-tube, the spray should shoot out from the mid range hole and dribble out from the idle hole.

 


3. Mikuni VM10-24 on Angel (TYM) mopeds

This carb is on Taiwan-made Angel and Speed Bird mopeds. It is a 10mm carburetor with a 20mm clamp diameter.

It is a 1960’s to early 70’s design, like a 1965 Yamaha U5 Newport, or a 1970 Suzuki F50 Cutlass carburetor. It has a brass swinging twin-float and a replaceable float needle seat. It has nothing made of rubber in it, unlike more modern carburetors. 

1977 Angel AP48

1983 Angel BP48-S carb

1979 Angel BP48-S

1977 Speed Bird BP48

 

 

 

 

 

 

 

Mikuni VM10-24

Parts List
 #    Angel part #  Trac#   price      description
00  786-01-31000 00000     N/A  carburetor assy
01  786-01-3100a 00000  $0.00 carburetor body bare
02  786-01-31510 00000  $0.00 cable rubber boot
03  786-01-3110a 00000  $0.00 carb top M20-1.0 thread
04  786-01-31440 00000    N/A  throttle spring Ø13 x 38 stiff original
04  786-01-3144a 00000  $6.00 throttle spring Ø13 x 50 soft substitute
05  786-01-31380 00000  $0.00 spring plate Ø13 Ø2.5
06  786-01-31340 13208  $2.00 needle clip Ø2.0
07  786-01-31330 00000    $15  jet needle 3G9  Ø2.00 Ø1.60 x 34.4
08  786-01-31470 00000    $45  throttle slide Ø16 x 23.5, says 2.0
09  786-01-3120a 00000  $5.00 cable adjuster-stop M6-0.75  hex7
10  786-01-3120b 10210  $3.00 adjuster lock nut M6-0.75 x 2 hex7
11  786-01-3120c 00000  $0.00 choke housing M10-1.0 thread, pipe thread subst?
12  786-01-31490 00000  $0.00 choke spring Ø6.5 x 23 stiff
13  786-01-31480 00000  $0.00 choke plunger Ø8 x 17.5
15  786-01-31520 13218  $1.50 clamp nut M5 x 5 hex9
16  786-01-31530 00000  $0.00 clamp screw M5 x 27 slot-hex8
17  786-01-31450 13211  $5.00 idle (both) spring Ø4.8 x 10
18  786-01-31460 00000  $6.00 idle air screw M6-0.75×19, long tip (-1)
19  786-01-31540 13210  $9.00 idle speed screw M6-0.75×17 short tip
20  786-01-31370 00000  $0.00 idle jet 15
21  786-01-31320 00000  $0.00 needle jet E2-137 Ø2.05
22  786-01-31300 00000  --N/A- main jet 45 M5-0.75 small hex
23  786-01-3139a 00000  $0.00 float seat seal washer Ø7 x Ø10
24  786-01-3139b 00000  $0.00 float valve seat M7-0.75 thread hex8
25  786-01-3139c 00000  $0.00 float valve needle
26  786-01-31350 00000     N/A  float
27  786-01-31410 00000  $4.00 float hinge pin Ø2.5 x 23
28  786-01-31360 00000     N/A  float bowl gasket
29  786-01-3100b 00000     N/A  float bowl
30  786-01-31430 10202  $0.70 float bowl screw M4 x 14 phillips
31  786-01-3100c 00000  $0.00 float overflow hose Ø3 x 200
32  786-01-3100d 00000     N/A  clamp sleeve with lip Ø20 x Ø23 x 15.5
34  786-01-3110b 10209  $6.00 cable adjuster-stop M6-0.75 x 16 female hex7
35  786-01-3110c 00000  $3.00 adjuster lock nut M6-0.75 x 2 hex7
36  786-01-3110d 00000  $0.00 carb top rubber cap
37  786-01-3110e 00000  $0.00 curved pipe cable guide

 

Angel Carb Service:

Angel service p9

Angel service p10

Angel service p11

Angel service p12

 

 

 

 

 

 

 

 

 

 

 


4. Mikuni design

A. Pacco

The India-made Pacco P-60 MT carburetor used on 2000-2002 Avanti mopeds

Pacco P-80 MT carburetor 21mm clamp diameter, same as Dellorto SHA 15/15

Pacco P-60 MT carburetor, 21 clamp diameter
Left, Dellorto SHA 15/15, same 21 clamp size

avanti-pacco-carburetor-16-0-mm-slide-and-top-parts

Pacco P-60 MT carburetor, 16mm slide parts

 

 

 

 

 

 

 

.

 

 

 

B. Mikcarb

The India-made Mikcarb is used on 2005 Hero Majestic Pacer. It looks identical to Pacco P-60, except it has a cable choke instead of a flip lever.

Mikcarb on 2005 Hero Majestic Pacer

 

 

 

 

 


5. Mikuni Jets

Small Hex used on 1960’s-70’s Yamaha and Kawasaki
045    --N/A-  Angel #786-01-31300
050      N/A

060      N/A

0
70    $3.00
0
75    --N/A-
080    $3.00
085    $3.00

090      N/A
100      N/A

Small Round used on many Yamaha, Kawasaki, and Suzuki products
060    --N/A- Indian #E236-00-50
062.5 $8.00  Indian #E236-25-50
065    --N/A-  Trac #13206
070    --N/A-  Trac #13207
0
75    --N/A-
080    --N/A-
090      N/A
100      N/A
110      N/A
116    $3.00
118    $3.00
120    $3.00
124    $2.50
132    $2.50
140    $3.00
150    $2.00
155    $2.50
160    $3.00

Large Round  used on many Yamaha, Kawasaki, and Suzuki motorcycles
060    --N/A-
062.5 $8.00
065    --N/A-
070    $8.00  Yamaha #620-14231-14-00
0
75    --N/A-
080    --N/A-
090      N/A
097.5 $2.50
100    $2.50
102.5 $2.50
105      N/A
107.5 $2.50

110    $2.50
112.5 $2.50
115      N/A
117.5   N/A

120    $2.50
122.5   N/A
125    $2.50
127.5 $2.50
130    $2.50
132.5 $2.50
135      N/A
137.5 $2.50
140    $2.50
142.5 $2.50
145   
$2.50
147.5 $2.50
150    $2.50

152.5 $2.50
155    $2.50
157.5 $2.50

 


6. Info

These are the baby Mikuni’s, the smallest of the small, 10 to 13mm for limited 50cc engines. Unlimited 50cc like Kawasaki AR50 or Yamaha YSR50 have 18mm size carburetors. Those are bigger babies, but still “off the charts”.

USA motorcycle parts suppliers commonly have parts for 28 to 44mm Mikuni VM series (classic round slide) carburetors. They have 2.5 or 3.0mm jet needles, not 2.0 like the “babies” have. Their float needles are also bigger.

Yamaha, Suzuki, and Kawasaki supply some parts for the small Mikuni carburetors that are on their 50cc models.

 

Carb clips

 

Jet Needle Clips are tiny and get lost easily. The full name of that kind of clip is “metric side-mount external retaining ring (E-style)”. The clip size for moped carburetors is smaller than any motorcycle carburetor clip, because the jet needle and everything else in the carburetor is smaller. A 10mm Indian moped carb jet needle is 2.0mm thick with a 1.5 clip groove. Mikuni carbs 18mm and up have needles 2.5mm thick with a 1.9mm clip grooves, or bigger.

 

 

 

 

Sources:

  1. Parts Catalogs provided illustrations, part numbers, descriptions, applications, and some specifications.
  2. Service Manuals provided most specifications.
  3. Packaging Labels on some new parts provided part numbers and applications.
  4. Markings on some used parts provided specifications.
  5. Direct Measurement on most parts provided specifications.
  6. Internet Images provided some identification by photo-matching, and occasionally dimensions by photo-scaling.

 

 


7. Tillotson Carburetor on 1978 Indian AMI-50

Tillotson carb kit

 

Tillotson Carburetor Parts (none)
    E210-12-50 Tillotson carb comp.   none  has no float reservoir
These have an adapter “bell” for the air filter, to interchange with Keihin.
These did not work well when they were new with fresh rubber back in 1978.
Tillotson carbs were replaced by Keihin, only months after they came out.
40 years later in 2018 their rubber parts, especially the diaphragm, are all stiff.
This is the Tillotson carb kit for Indian, Rk-32Hk, available on Amazon.

 

 

Tillotson carb, front and back view

Tillotson carb on 1978 Indian

 


Gurtner Carburetors

July 14, 2016

Gurtner

Contents (carburetor families):
1.  AD  on ’81-83 Motobecane  
 

2. D, E on ’75-83 Peugeot 102, 103
3. AR2 on ’70-80 Motobecane 40, 50
4. AR1 on ’66-78 Motobecane 7, Cady
5.  BA  on ’60-69 Motobecane, Raleigh
6.  AR  on ’55-65 Motobecane, Riverside

7. Floats
8. Jets
9. More  

 

Jules Gurtner started making carburetors in 1907, for some of the earliest automobiles and motorcycles.

Gurtner carburetors are made in France, and original on French mopeds Peugeot and Motobecane. See also mopedarmy.com

Gurtner early M18D M20D M22D M23.5D M25D

1940’s M series

Gurtner early M series article from 1945

1945 M series

 

 

 

 

 

 

 

 

Gurtner Master Catalogs: Here are the 1961 Gurtner Catalog and the 1980 Gurtner Catalog from motobec.fr. 

Gurtner Moped Carburetors: Here are the 1961 Carb List and the 1980 Carb List. From those you can see that about one third of all Gurtner carbs are for mopeds (mobylettes). Before 1960, most Mobylettes had 10mm carburetors (or 8.7). So the speed and power were limited to be under about 25mph. After 1959, some had 10mm carbs and went 25mph, and some had 13mm carbs and went 30-35mph.

Much of this information and photos are from the Motobecane Club of France.

 

 


M

1. Gurtner AD

 

AD was the last Gurtner carburetor on Motobecane/MBK mopeds, before the change to Dellorto SHA.

AD Carb List

AR2float 0 slide 0000 jet  000 diffuser       air box
float 000 slide 00000  jet  000 diffuser   assm.   bare

∅13 AD13-858-A  7/82  parts list
1980’s Motobecane 99Z, 94Z
13105  13138 ∅15? 9831/78   13345 0  13104  13185

∅13 AD13-915   parts list
1980’s Motobecane/MBK 51V
13105  13416 ∅15? 9831/78   11316 0  13534  11301

∅13 AD13-945   parts list
1980’s Motobecane/MBK 51S
13105  13416 ∅15? 9831/76   14097 0  13534  11301

 

 


2. Gurtner D and EPeugeot 1980 tiny

D8.5G, D10G, D12G, E12B carburetors
1975-83 Peugeot 102, 103 (US models)

 

Gurtner Peugeot remake

generic D12G remake

Gurtner D12G-724F

 

 

 

 

 

 

 

 

1980 102 SP U3 D12.698.G.1.80

Gurtner D12G-698

 

 

1980 Peugeot 102 SP U3 with
Gurtner D12G-698 carburetor
says D12.698.G.1.80 (Jan 80)

 

 

 

 

102 has a fixed engine and piston port intake, to cylinder.
103 engine swings and has a reed valve intake, to case.
USA versions: U1 (20 mph), U2 (25 mph), U3 (30 mph)

Left, 102 has a fixed engine and piston port intake, to cylinder. R, 103 engine swings on the swing arm pivot, case reed intake.

 

D, E Carbs

AR2float 0 slide 0000 jet  000 diffuser       air box
float 000 slide 00000  jet  000 diffuser   assm.   bare

∅12 D8.5G-826 
1976-80 Peugeot 103 U1 (20)
6437  4649/10 ∅00 5012/240=60 fixed  9860  9860

∅10 D10G-754B  parts list
1970’s Peugeot 103? mofa (25kph)
6437  4649/10 ∅00 5012/250=63 fixed  9860  9860

∅10 D10G-918B  parts list
1970’s Peugeot 103 CH (30kph)
6437  4649/10 ∅00 5012/230=58 fixed  9860  9860

∅10 D10G-975 
1980 Peugeot 102 SP U2 (25)
6437  4649/8 ∅13   5012/220=56 fixed  9388  9388

∅12 D12G-698  1/80
1980 Peugeot 102 SP U3 (30)
6437  4649/8 ∅13   5012/245=62 fixed  9388  9388

∅12 D12G-724E  parts list
1970’s Peugeot 104 L, LV
6437  4649/8 ∅13   5012/245=62 fixed  9860  9860

∅12 D12G-724C
1976-80 Peugeot 103 U2, U3 (25, 30) 
6437  4649/8 ∅13   5012/245=62 fixed  9860  9860

∅12 E12B-738
1981-83 Peugeot 103

 

 

 

Part numbers: Peugeot is olive, Motobecane is dark orange.
102 and 103 combined. Part numbers with “b” are 102-only.
New items prices are green. Used prices are dark green.

no. price   Peug#  Gurt#  MB#  description   remarks

1    $78.0 48929 carburetor Ø12 D12G -724F
1    $00.0 48929 modern genuine with air box
1    $00.0 48929 jet 64, replaces D12G-724C
1    none  48929 carburetor Ø12 D12G -724C
1    none  48929 jet 245=59, for 103 U2, U3
1    none  58036 carburetor Ø8.5 D8.5G-826
1    none  58036 jet 240=58, for 103 U1
1b   none  46479 carburetor Ø12 D12G -698
1b   none  46479 jet 245=59, for 102 U3
1b   none  64203 carburetor Ø10 D10G -975
1b   none  64203 jet 220=54, for 102 U2
2    $45.0 48929 carb 48929 bare   good used, tested
3    $15.0 69299 4649/8 15319 throttle slide Ø13 
3    none  69445 4649/10 throttle slide Ø?? for D8.5G-826
4    $5.00 53386 17732 14107 spring Ø9.5 x 30
5    10-$7 12156 carb top bare
5    $12.0 12156 7701 top assy 5,6,8,9,10,12,13  no slide
6    $1.00 07016 10218 14311 screw M4 x 12 
7    $4.00 09939 9939 air filter bracket
7b  $0.208560993660 01088 lock washer   
8    $5.00 01510 1510 00189 adjuster M6-0.75 
9    $2.50 001511 1511 04172 adjuster nut      
10  $3.00 08947 8947 drawing rod washer 
11  $8-$5 09394 9394 drawing rod gasket 
12  18-12 09393 9393 drawing rod 
1
$8.00 09391 9391 throttle pull clip  a wire “crankshaft”
14  $2.00 06546 6546 18892 idle screw M5-0.8
15  $2.00 05072 5072 00204 idle screw spring
15  none  06546 13667 idle screw and spring
16  none  69463 5012/66 jet 260=66 0.64  (0.025″)
16  none  69462 5012/64 jet 64=255  
16  none  69461 5012/63 jet 250=63 0.63 mm
16  $19.0 69460 5012/62 jet 245=62 0.62 mm
16  $11.0 69459 5012/60 jet 240=60 0.60 mm
16  $14.0 69458 5012/59 jet 235=59 0.59 mm
16  $14.0 69457 5012/58 jet 230=58 0.58 mm
16  none  69456 5012/56 jet 220=56 0.56 mm
17  $2.00 69300 fiber washer 19 x 12.5 x 0.4   optional
18  55-35 69755 float cover w/seat     
19  $5.00 09348 9348 rubber ring 22 x 27 x 1  
20  $5.00 69754 12372 plug M12-1.0 taper seal, no gasket
21  $2.00 08048 8048 float cover strap  for 103
21b $12.009365 9365 float cover strap  for 102
22  $0.60 10306 10306 13392 screw M5 x 10       
23  $24.0 06437 6437 float with needle Gurtner         
23  $14.0 06437 5440 float w/needle aftermarket
24  $8.00 04159 4159 14133 fuel filter screen
25  none  09860 9860 air box with filter   for 103
26  $12.0 09672 9672 air filter gasket          
26b$39.0 09388 9388 air box with filter   for 102
27  $18.0 09286 9286 air filter step-screw for 103
27b none 09395 air filter step-screw   for 102 (use 103 type)
28  $1.00 68239 9617 19689 screw M3-0.5 x 6
29  $6.00 68239 clamp bolt M6 special  
30  $0.4083208700010 clamp bolt nut
31  $10.0 68202 23134 mount clamp w/bolt  

 

1970's 103 types had Gurtner D12 carburetors. '81-on 103/104 had Gurtner E12B carburetors.

1970’s 103 types had Gurtner D12 carburetors.
’81-on 103/104 had Gurtner E12B carburetors.

 

 

 

 

 


3. Gurtner AR2 M

 

Gurtner AR2 series moped carburetors have a large flange, like a wall. It is for an “air box”, a noise silencing, fuel mist recovering, and air filtering chamber. There are two (venturi) sizes, 10 or 12 mm, and two styles, side or center mount. Center and side mount carbs look the same, but don’t interchange completely.

Gurtner AR212/R705 remake

AR2-12-705 remake

Gurtner AR210-R991

Gurtner AR2-10-991

 

 

 

 

 

 

 

 

Motobecane 30mph variator side-mount carb with long pipe

side mounted AR2 carburetors

 

Motobecane 20mph no-variator side-mount carb with thin long pipe

side mount thin pipe

40TS side mount with top-pull choke

 

 

 

 

 

 

 

Side mount carburetors have threads for an air filter stud, side holes for a center mount air box clip, and clamp to a 19mm intake pipe. The side mount float top cover has a vertical fuel hose spigot. A stripped bare side mount body, as is, will exactly replace a bare center mount body.

 

Motobecane 30mph variator center-mount carb with short pipe

center mounted AR2 carburetors

Center mount carburetors have no threads in the stud hole, side holes for a center mount air box clip, and have removable sleeves, black 16 x 19 (for AR210), and white 17 x 19mm (for AR212). The sleeves reduce the precision clamp size from 19mm to 16 or 17. The purpose is to be tamper resistant. The sleeves fit tight and are difficult to remove without damaging them. The center mount float top cover has a horizontal fuel hose spigot. A stripped bare center mount body, after threads are cut in the air box post hole, will replace a bare side mount body.

Center mount early  Some pre-USA years 1960’s or early 1970’s had no fuel hose inlet in the float top cover. Instead it was in the carburetor body just below the float top. This type is in many Motobecane USA parts illustrations, but it was not used on any, or hardly any US models. In the illustration below it was edited out. Out of 47 original carbs, taken off once-living Motobecanes from around Southern California, none were this “center mount early” type with the fuel hose spigot in the carb body.

 

OEM Replacements Motobecane USA 1976-80  
7776
is pre-1978 12mm, 5mm stud, thin mount.

13512 is 1978-on 12mm, 6mm stud, thick mount.
13510 is 1978-on 10mm, 6mm stud, thick mount.

In 1977 the air box stud 5 mm threads would sometimes get stripped, or the clamp mounts would sometimes break. So during 1978, on some they made the air box stud 6 mm and the casting thicker at the mount. From 1979-on all were 6 mm.

MB carb mounts early (thin) and late (thick).

MB carb mounts
early (thin)
and late (thick).

 

Mount Type: All Motobecane carbs clamp to 19.0mm inlet pipes. But many of the pre-March 1978 carburetors were cracking at the edge of the clamp, or the base of the petals. So Gurtner beefed up the carb body with a reinforcing ring, made the clamp petals about 1mm thicker each, and changed the clamp to the bigger Peugeot double-wall type.

Air Filter Stud: When the mount was made stronger in 1978, the air filter post was also beefed up from 5mm to 6mm. This made the threads in the body more resistant to stripping. Another issue that was improved is when the air filter stud is over tightened, a bulge can form in the float chamber wall behind it. That bulge makes the float stick. See below.

Center Mount Air Cover: The center mount type (short and deep) air box is too deep and sticks out too much as a side mount. The right side engine cover panel must be removed, and some kind of high-offset right pedal crank arm installed. Then maybe pedal threads are different.

Side Mount Air Cover: The side mount type (tall and flat) air box is too tall and hits the frame as a center mount. More importantly, they break, fall off, and get thrown away, in addition to getting lost. Because of that, they have become scarce and pricey. From 2000-2015 maybe 200 people have asked for this item, but only two were available and sold at MM.

Gurtner Motobecane air box covers

Three views of the side (L) and center (R) types of MB air box covers

 

Motobecane side mount air box nut and cupped washer upgrade

Side mount air cover breaks without cupped washer/nut.

The Motobecane piston-port two-stroke engine needs the air cover because the gasoline mist flows in and out in both directions. So there is a little cloud of fuel and oil mist out in front of the carburetor. Without the air cover, this fuel cloud gets wasted and blown away (or ends up on the riders right leg or shoe). Besides that, the air cover provides the correct amount of flow restriction, which is a good thing, up to a point. See below about running without an air cover (how it can damage the engine by over-heating from not enough fuel and oil).

 

 

 

 

 

Air cover substitution: Here is a center-mount air cover installed on a side-mount carburetor. Holes have to be drilled for the mounting wire clip, and the lower right corner has to be warmed up and molded inward where it touches the round magneto base plate. More importantly, the side cover must be removed, and it almost touches the pedal. So it’s easy to kick it when pedalling.

 

AR2 Carbs

AR2float 0 slide 0000 jet  000 diffuser       air box
float 000 slide 00000  jet  000 diffuser   assm.   bare

∅10 AR2-10-910  parts list  side mount B
54115 (use 13510), bare 52435, stud 5
77-78 MB 50V (20mph) to 12/78
4901  4649/10 ∅13  581/52  9529/3=20573  12330

∅10 AR2-10-737 and 991  3/77-11/79 center mt. A
52175 (use 13510), bare 52430,
77-79 MB 50V (25 mph) 4/77 on
4901  4649/10 ∅13 0 K80 00 0000/0=52560  12330

∅12 AR2-12-705  7/75-01/77 center mount A
20026 (use 7776), bare 53657,
75-77 MB 50V (30) to 3/77, AV88, 68, 49, 40, 50
4901  8474/6 ∅14  581/B54  9346/1=19990  8437

∅10 AR2-12-729  11/75-1/79 side mount B
22160, bare 54466, pre-78 is stud 5 (use 7776)
22160, bare 54466, 78-on is stud 6 (use 13512)

74-79 MB 40, 50 (25 and 30 mph)
4901  8474/6 ∅14  581/B56  0000/0=21002  12330

∅12 AR2-12-873  3/77-11/79 side mount B
54973, bare 54466, pre-78 is stud 5 (use 7776)
54973, bare 54466, 78-on is stud 6 (use 13512)

77-79 MB 50V (30 mph) 4/77-3/80
4901  8474/6 ∅14  581/B56  0000/0=22937  12330

∅12 AR2-12-978  4/80  side mount B
77-79 MB 50V (30 mph) 4/80-12/80
4901  8474/6 ∅14  581/B56  0000/0=22937  12330 

∅13 AR2-13-712
19xx Motobecane SP94
4901  slide ∅14

 

Key: A = center mount carb only   B = side mount only

New prices are green. Used prices are dark green.

 

  pic  price  MB no.   description          remarks
    A $110  20026 carb AR2-12-705  no air cover
    A none  52175 carb AR2-10-991
    B $180  54973 carb Ø12  7776     no air cover
    B none  54973 carb Ø12 13512    no air cover
    B $120  22160 carb AR2-12-729  no air cover
    B none  54115 carb Ø10 13510 
  1A $65.0 53657 Ø12 carb bare   for AR2-12-705
  1A none  52430 Ø10 carb bare   AR2-10-991 & 737
  1B $50.0 54466 Ø12 carb bare   AR2-12-873 & 729
  1B none  54235 Ø10 carb bare   for AR2-10-910
  2A $39.0 18355 air filter cover   for center mount
  2B none  20949 air filter cover   for side mount
  3A $12.0 15041 air filter screen  for center mount
  3B $6.00 20999 air filter screen  for side mount
  4A $12.0 18356 spring clip         for center mount
  4B $4.00 m6cup cupped washer upgrade, see above
  5B $1.00 m5lock M5 nylock nut   for M5 stud
  5B $1.00 m6lock M6 nylock nut   for M6 stud
  5B $2-$1 13339 M5 knurled nut  for M5 stud
  6B $5.00 21000 stud 5mm         side mount pre-79
  6B $8.00 23562 stud 6mm         side mount 78-on
  6B $5.00 special M6-M5 step stud for stripped M5 hole
  7B $3.00 20997 air filter gasket  18 x 21 x 1.5mm
  8B $8.00 20996 air filter 5mm     side mount pre-79
  8B $20.0 23561 air filter 6mm     can drill a 5 to 6
  9   $1.00 19689 taper screw M4-0.7 x 6/8 on USA models
10   $1.00 19767 bolt M5-0.8 x 44    M5 w/flange 10 hex
11   $2.00 15326 fiber washer 5mm 5 x 10mm
12   $6.00 20475 o-ring 21×24 x 1.5  this is optional
12   $0.00 somehow, removing this often makes it leak less
13A $5.00 00189 adjuster M6-0.75   A13
13B $16.0 21940 cable guide, used   for side mount
14   $0.50 18893 screw M5-0.8 x 12  
15   $0.20 01271 washer M5           
16A $12.0 21229 slide cap M6-0.75   threaded for adjuster
16B $5.00 21696 slide cap                recessed for elbow
17   $5.00 14107 spring Ø9.5 x 30    same as Peugeot
18   $15.0 15319 throttle slide Ø13   for AR210 & Peugeot
18   $15.0 19278 throttle slide Ø14   for AR212 carbs
19   $7.00 14120 choke spring       
19B $2.00 22935 choke cable ring    cable end adapter
20   $9.00 14119 choke slide brass   stepped 6.3 x 5.7 x 15
20B $8.00 22936 choke push rod      original white plastic
20B $3.00 22936 substitute (adjuster A2)
21   $2.00 00204 idle spring 7.5 x 11 
22   $2.00 18892 screw M5-0.8 x 16  same as Peugeot
23   $5.00 00208 bolt assy M6-1.0 
24   $3.00 00878 tall nut M6-1.0   12mm tall 8mm hex
25   $2.00 15043 clamp for ∅21.7 (to 3/78)
26   $10.0 23134 clamp for ∅23.5 (4/78-on) 
26A none  14100 sleeve 19×16 black   for AR2-10-991
26A $21.0 16630 sleeve 19×17 white  for AR2-12-705
26B none   22689 rubber washer 15 x 19 x 2
27   $9.00 18880 float gasket   
28   $8.00 14133 fuel filter/screen     same as Peugeot
29   42-25 14101 4901 float Gurtner 41.4 x 23.6 
29   $12.0 14101 float aftermarket   40.3-40.9 x 22.6-22.7
30B $38.0 22937 slide diffuser Ø0.91  AR2-12-873 & 978
30A $7.00 19990 slide diffuser Ø1.50  for AR2-12-705
30A none  20573 slide-fit diffuser Ø?   AR2-10-910 pre-78
30A none  54237 slide diffuser Ø1.50  AR2-10-910 ’78-on
30B $35.0 21002 slide diffuser Ø0.91  for AR2-12-729
31   $3.00 20000 collar M7-1.0           holds slide-fit diffuser
32   $1.00 19689 screw M3-0.5 x 7     M3 taper seal
33   none  52560 press diffuser Ø0.61 AR2-10-991 & 737
34A none  21228 float top horiz inlet   for center mount
34B none  22161 float top vert inlet    for side mount
35   none  22339 float top no inlet      for carb w/inlet
36   $17.0 23545 581/52 jet 0.52 mm 210cc  for AR2-10-910
36   none  21841 581/52 jet 0.52 mm   #52  
36   $10.0 23546 581/54 jet 0.54 mm 220cc  for AR2-12-705
36   $14.0 21843 581/54 jet 0.54 mm   #54  for 
36   $19.0 23547 581/56 jet 0.56 mm 230cc  AR2-12-873 & 978
36   $19.0 21949 581/56 jet 0.56 mm   #56  for AR2-12-729
36   $15.0 00000 581/57 jet 0.575mm   #00 drilled w/#74 drill
36   $19.0 23548 581/58 jet 0.58 mm 240cc  for AR1-10
36   $19.0 22938 581/58 jet 0.58 mm   #58  
36   $19.0 23549 581/60 jet 0.60 mm   #60  for AR1-10
36   $15.0 00000 581/61 jet 0.615mm   #00 drilled w/#73 drill

36   $15.0 00000 581/64 jet 0.64 mm    #00 drilled w/#72 drill
36   $19.0 51052 000/00 jet 0.80 mm   K80  AR2-10-991 & 737
40   $17.0 aftermarket AR2 Carb Kit correct only for AR2-12-705

Choke Slide: This is often mysteriously missing, but actually stuck in the lowest (normal) position, either by tar or corrosion. It can be unfroze with solvent and/or by removing the cable wire and pushing it up from the bottom by tapping with a small punch and hammer. When the choke slide is pulled up, the choke is “on” for cold starting, and an extra fuel path is exposed by the step in the choke slide. If the choke slide is actually missing, the choke would be “on” all the time, but some extra air gets in along with the extra fuel. So the net effect of running without a choke slide is minor. 

Top Pull or Bottom Pull Choke Cable:

1. On center mount carburetors, for variator models, the choke cable is “top pull”. The choke and throttle cables detach, allowing the carburetor to be serviced away from the bike.

Gurtner MB Top pull choke cable routing

Gurtner AR2 top pull choke cable routing

2. On side mount carbs for non-variator (Dimoby) models, the choke cable is “top pull”, but has a elbow (curved tube), like the throttle cable. The choke and throttle cables detach, allowing the carburetor to be serviced away from the bike.

Gurtner MB bottom pull choke parts exposed

AR2 bottom pull choke parts exposed

3. On side mount carbs for ’78-later 30mph variator models, the choke cable is “bottom pull”, where the choke wire runs through the carb body, trapping it on or near the bike. On those most service operations are done with cables attached, about one foot away from the bike. To remove the carb you have to pull the choke wire all the way out. Then it won’t usually go back because the braided end gets frayed. Then the choke wire has to be replaced. 

 

 Le Diffuseur: When you look down the “throat” or venturi of a Gurtner carburetor, with the throttle wide open (throttle slide up and out of the way of the air), the little brass tube that sticks up from the floor of the venturi is the diffuser. It sprays the gasoline mist sucked up by the moving air.

Left, top are the way more common type, the “slide fit” type diffusers. Can you see, besides the main large hole down the middle, that each diffuser has two small holes facing out of the page? Those are the idle holes. When they are blocked, the engine will run OK, but will not run slow or “idle”. On a 21002 diffuser the idle holes are 0.016″. That size hole is cleaned with a #78 drill, also 0.016″.

Left, bottom are the less common type, the “press fit” type diffusers. You can only see one idle hole on this kind, but there is another on the opposite side. These diffusers have a very small center hole, that serves has the limiting jet. They are installed by pressing in from above, instead of sliding in from below like the other kind. The purpose of this type is to be tamper resistant. There is no particular direction that they have to be aimed at, and no flat side in the carb body for that purpose.

 


Additional Information:

Motobecane 20mph carb sliced in half

Slide Fit and Press Fit Diffusers: Some Motobecane carburetors have “press fit” diffusers, instead of the usual “slide fit”. This is one of those types (AR2-10-737 or AR2-10-991 or perhaps others) that has been sliced in half to expose it’s secrets.

While “slide fit” diffusers slide in and out from the bottom, this “press fit” diffuser 52560, and carburetor type, slides (presses actually) in or out from the top. Many of these get smashed on top by Motobecane mechanics trying to push the diffuser downwards, the normal way out.

Press-fit-diffuser carburetors cannot be made to accept slide fit diffusers. 

 

Motobecane Choke Circuit cut away

Choke (cold starting) system: Unlike the Peugeot Gurtner and most other moped carburetor chokes, the Motobecane Gurtner AR2 has an additional fuel path or tunnel. It’s “choke” is a fuel enrichment device rather than an air restricting device. The choke circuit is completely independent of the main fuel circuit. It has it’s own fuel tunnel out of the float bowl, that bypasses the throttle slide, diffuser, and jet. 

Original Equipment Carbs have Dates: This carburetor clearly shows it’s manufacture date of 5/77, below the model number. It could be from a late 1977 or a 1978 bike. The 39 used Gurtner AR2 carburetors in Myrons Mopeds inventory on Dec 2014 have dates ranging from 03/74 to 04/80. The majority are from 1977 and 1979. See above “Population Study of Gurtner AR1 and AR2 Carburetors in Southern California”.   

 

 

 


M4. Gurtner AR1

 

Parts for five Gurtner AR1 carburetors are listed here, combined into one list using quantity colums a,b,c,d,e. 

 

a. Gurtner AR1-10-674 ’66-68 Motobecane Cady M1

 

b. Gurtner AR1-10-691 ’66-78 Cady M1P, PR, PRT, PRTS

MB Cady and MB 7 air boxes

 

c. Gurtner AR1-11.5-753 ’74-77 Cady M3PR, PRT, PRTS

 

d. Gurtner AR1-10-919 ’78 Motobecane 7 (US 20, 25)
e. Gurtner AR1-12-884
’78 Motobecane 7 (US 30mph)

1978-79 Motobecane 7

Gurtner AR1-12 carburetor complete 3 views

In US mopeds, AR1 carburetors were only on one model for one year. That lone French pony was the 1978 Motobecane Model 7. Only about 2 or 4% of the Motobecanes sold in the US were Model 7.

 

AR1 Carb List

AR1float 0 slide 0000 jet  000 diffuser       air box
float 000 slide 00000  jet  000 diffuser   assm.   bare

∅10 AR1-10-691  parts list
1966-78 Cady M1P, PR, PRT, PRTS
5186  8686 ∅00 00 581/B53    fixed 00  7679  4909

∅10 AR1-10-A691  parts list
1974-77 Cady M3PR, PRT, PRTS export
6758  8686 ∅00 00 581/B52    fixed 00  7682  11021

∅11.5 AR1-11.5-753  parts list
1974-77 Cady M3PR, PRT, PRTS
6758  4685/12 ∅00  581/B55   fixed 00  7681  11021

∅10 AR1-10-+919   parts list
1978 Motobecane 7 (20)
5186  8686 ∅00 00 581/B60   8669/1    7783  13289

∅10 AR1-10-919  3/78 parts list
1978 Motobecane 7 (25), 70’s M7
5186  8686 ∅00 00 581/B58   8669/2    7783  13289

∅12 AR1-12-884  11/77 parts list
1978 Motobecane 7 (30), 70’s M7
5186  4685/1 ∅14  581/B54   4687/3    7783  13289

 

Gurtner MB7

pic abcde price   MB#   Gurt#   description    remarks 

00 10000 none  00000 carburetor Ø10 AR1-10-674
00 01000 none  19600 carburetor Ø10 AR1-10-691
00 00100 none  00000 carbur.    Ø11.5 AR1-11.5-753
00 00010 none  54458 carburetor Ø10 AR1-10-919
00
 00001 none  23021 carburetor Ø12 AR1-12-884
01 00001 none  54454 7782 carb body bare Ø12
01 11010 none  54225 carb body bare Ø10
02 00111 $2.00 23194 9754 top screw M4-0.75 x 22
02 11000 $2.00 17760 top screw M4-0.75 x 20
03 00111 $0.20 01088 3650 washer M4 lock
03 11000 none  00943 washer M4 lock
04 11111 none  17759 8002 carb top
05 11111 $7.00 14120 3936 choke spring    
06 00011 $9.00 14119 3935 choke slide  
07 11111 $5.00 14107 3771 throttle spring 9.7 x 29
08 11010 none  19605 8086 throttle slide Ø12  
08 00101 $35.0 16629 4685/1 throttle slide Ø14
09 11111 $2.00 00204 5072 idle screw spring
10 11111 $2.00 18892 6546 idle screw
11 11111 $5.00 00208 bolt assy
12 11111 $2.00 15043 4330 clamp
13 00111 none   22689 7088/1 seal ring 15 x 19 x 2
14 
01000 none  19215 581/B48 jet 19 = 195cc = 48
14 01000 none  18973 581/B52 jet 20 = 210cc = 52
14 0000$10.0 23546 581/B54 jet 22 = 220cc = 54
14 00010 $19.0 23548 581/B58 jet 00 = 240cc = 58
14 00010 $19.0 23549 581/B60 jet 24 = 245cc = 60
15 00011 none  23196 7783 air filter assy
16 00011 none  23195 13288 air filter mount
17 00022 none  23139 13432 screw M5x10 allen
17 00022 $0.60 subst. screw M5x10 phillips
17 22200 none  19248 screw M4x10
18 00011 none  14123 5186 float
18 11100 none  16113 6758 float
19 11111 none  14103 3764 float gasket
20 00022 $0.20 01088 3680 lock washer M4
22 22200 $0.20 00943 subst. lock washer M4
21 00022 $1.00 14106 10218 float screw M4x12 phillips
22 00011 none  19143 3752 fuel filter
23 00011 $2.00 15326 14025 fiber washer 5×10
24 00011 $0.60 13245 8176 bolt M5x10 hex
25 00122 $16.0 21940 cable guide 
26 00011 none  23197 13289 air box
27 22222 none  19606 10271 wood-type screw 4 x 13
28 11111 none  19145 8523 air box clamp assy
29 00011 $50.0 23199 12931 float chamber cap

 

 

 

 


M5. Gurtner BA

 

 

1962 Riverside 14030

BA Carb List

BAfloat 0 slide 00000 jet  000 diffuser       air box
float 000 slide 00000  jet  000 diffuser   assm.   bare

∅10 BA10-549-D (BA-549-D)  7/60  parts list
1960 Mobylette
6685  4649/10 ∅13  5012/19    fixed 00  6747  4022

∅10 BA10-540-F (BA-540-F) 2/62 parts list  photos 1 2 3 4
1962 Riverside 14030
6685  4649/10 ∅13  5012/20    fixed 00  6747  4022

∅10 BA10-610-B (BA-610-B)  5/63  photos 1
1963 Raleigh RM6 Runabout
6685  4649/10 ∅13  5012/20?  fixed 00  6747  4022

∅10 BA10-610 (BA-610)  parts list  photos 1
1962 Motoconfort AU65, 60’s AV44, 76, 85
6685  4649/10 ∅13  5012/21, 20 fixed   6747  4022

∅10 BA10-610-C (BA-610-C)  10/63  photos 1 2 3 4
1962 Motobecane AV48
6685  4649/10 ∅13  5012/19   fixed 00  6747  4022

 

 

 


M6. Gurtner AR

 

 

1960 Riverside 14011

AR Carb List

ARfloat 0 slide 00000 jet  000 diffuser       air box
float 000 slide 00000  jet  000 diffuser   assm.   bare

∅10 AR10-429  parts image
1957-60 Riverside 14007A, 14010A, 14010B
5186  14124 ∅13 00  01122 0014126  00 000  15037

∅10 AR10-501  7/57  parts list
1957 Motobecane AV78 (variator)
5186  3100/10 ∅13  3983/21  5523 00  6747   4022

∅10 AR10-511  parts list
1950’s Motobecane, Dimoby (no variator)
5186  3763/8 ∅13 0 3983/20  5370 0    5946   5782

∅13 AR13-488-K  6/60  parts image
1960-62 Riverside 14010, 14010C, 14011, 14011A
5186  4685/14 ∅14  3983/21  4687 0 6904/2  4022

∅13 AR13-488  parts list
1961 Motobecane AV87 
5186  4685/14 ∅14  3983/21  4687 0 6904/2  4022

 

 

 

 

 


7. Gurtner Floats

 

Gurtner Floats

Gurtner 6437 and 4901

On 1970’s US mopeds there are 3 Gurtner floats:
5186 (Motobecane 14123) for AR1 carbs on Model 7

4901 (Motobecane 14101) for AR2 carbs on 40, 50
6437 (Peugeot 06437) for D-type carbs on 102, 103

Gurtner used to color code their new float containers green for Motobecane and red for Peugeot. Otherwise they are almost indistinguishable, unless together side by side. 

5186, 4901, 6437 specs

6685 specs

Float Service: On plastic types the needle is a press fit into the top and bottom holes in the bulb. The needle can simply need moving up or down. Or it could also need the tip straightened and/or sharpened/machined. Or the needle could need to be replaced, if it has become too short or too bent. Any piece of 1.5mm brass rod, cut to these lengths, and machined to a cone tip, would restore the float. In addition, a gasoline-proof sealant should be used to seal the press-fit holes, as a precaution, or if gasoline enters the bulb. 

Float List

Most data are from lesolex.com in France.
Most of these floats can be purchased there.
US models in blue.

13160 brass  for
needle ∅1.5 x 37.8, bulb ∅22.2
for chamber ∅23.4

1950’s Peugeot
superseded by 6437

13155 brass  for
needle ∅1.5 x 41.5, bulb ∅24.0
for chamber ∅25.2
1950’s Motobecane
superseded by 4901

6758 brass  for AR and AR¹ carbs
needle ∅1.5 x 41.7, bulb ∅22.7
for chamber ∅
for 66-78 Motobecane Cady
Motobecane #16113

5186 brass  for A, AR, AR1 carbs
needle ∅1.5 x 41.5, bulb ∅22.5 x 20.3
for chamber ∅23.6-23.9

’57-64 Ward (except 14030), 78 MB7
high bulb, Motobecane #14123

3739 brass  for C carbs: C10D
needle ∅1.5 x 41.7, bulb ∅22.5 x 20.3
for chamber ∅

for Peugeot Bima
low bulb, Peugeot #03739

6685A brass  for B, BA, BR carbs
needle ∅1.5 x 35.7, bulb ∅22.2 x 20.5
for chamber ∅23

60’s MB, Raleigh, ’61-63 Ward 14030
Motobecane #

6437 plastic for D carbs: D8.5 D10 D12
needle ∅1.5 x 37.8, bulb ∅22.0 x 20.1
for chamber ∅23.4

76-83 Peugeot 102, 103, 70’s BB
Peugeot #06437

4901 plastic for AR2 carbs
needle ∅1.5 x 41.5, bulb ∅24.0 x 20.3
for chamber ∅25.2

74-80 Motobecane 40, 50, others
wide bulb, Motobecane #14101

4901/2 plastic for E carbs: E12
needle ∅1.5 x 41.5, bulb ∅24.0 x 20.3
for chamber ∅

81-83 Peugeot 103, 80’s 104, GT10
wide bulb, Peugeot #

13105 plastic for AD carbs: AD13
needle ∅1.5 x 41.5, bulb ∅25.2 x 20.6
for chamber ∅

1980’s MBK 51, M16, 99Z 92GT
wider bulb, MBK #23135

 

 

 

 


8. Jets

There are three types of Gurtner jets (gicleurs), 581, 5012, and 9831. 

5012

M6-0.75 thread

 

 

581

M7-1.0 thread

 

 

9831

M7-1.0 thread

 

 

 

There are three size label types, here called 60’s, 70’s and 80’s.
A  581  jet, 60’s size 21, equals 70’s size 215, equals 80’s size 53.
A 5012 jet, 60’s size 21, equals 70’s size 215, equals 80’s size 54.
A 9831 jet, 60’s size 00, equals 70’s size 215, equals 80’s size 55.

Use this table to cross reference Gurtner sizes.

 

 


9. More

 

 

Population Study of Gurtner AR1 and AR2 Carburetors in Southern California

These 47 Motobecane carburetors all came from whole bikes that were stripped out for parts. The Motobecane population in the greater Los Angeles area is roughly represented by this large subset. Out of 47 carbs there were only two AR1 types, from Model 7. All of the 45 others were from Models 40 and 50. 

Year  Qty  Carb Type   Mount   Dates


1974   1  AR2-12-774   center  03/74


1975   7  AR2-12-705   center  07/75 07/75 07/75

1975   6   AR2-12-729   center  11/75 12/75 12/75 12/75


1976   8  AR2-12-705   center  01/76 01/76 01/76 01/76 01/76 03/76 10/76

1976   5   AR2-10-759   center  06/76


1977  13  AR2-12-705   center  01/77

1977   10  AR2-12-873     side   03/77 04/77 05/77 06/77 11/77 12/77 12/77

1977   10  AR2-12-729   center  02/77 04/77

1977   10  AR2-10-737     side   05/77

 1977   10 AR1-12-884    —–    11/77  11/77


1978   6  AR2-12-873     side   01/78 05/78 05/78 11/78 11/78

1978   1  AR1-10-919     side 03/78


1979   9  AR2-12-729   center  01/79

1979   9   AR2-12-873     side   03/79 05/79 05/79 05/79 06/79 07/79 07/79 11/79


1980   4  AR2-12-978     side   04/80 04/80 04/80 04/80


total  47

These are the surviving Motobecane carburetors that lasted longer than the rest of the bike. If there were times when the metal was weak, those months or batches would be missing from this collection, pretty much, because the ones that tended to break already broke and were thrown away. It seems like 1978 is missing some survivors, mysteriously. Perhaps they were used as upgrades/replacements for 1976-77 thin-mount ones that broke. You can see from this sub-population that early carburetors were center mount, and late ones were side mount, and in between was both.

 

 

 


Dellorto SHA

December 24, 2014

 

Dellorto SHA is a family of Italian moped or mini-bike carburetors. SHA’s have flat throttle slides and no jet needles. They all have the same outer size and main body appearance, with a 59mm round flange for an air filter. They have been produced for in Italy from the 1960’s to the 2000’s. In particular the Dellorto SHA 14/12 and 14/9 carburetors were on tens of thousands of US mopeds from 1976 to 1985.

Arbeo-Dellorto SHA carbs were made in Spain under license for the Spanish moped Derbi. They were more goldish colored, and tended to leak fuel past the float seat.

Generic SHA: Since the 2000’s there are China made remakes. Most have different screw threads, not Italian-metric. Many have M5-0.80 jet threads, different from Dellorto M5-0.75. The Runtong remake carb has M5-0.75 jet threads. So it can take any Dellorto M5 jet, but many other generics cannot.

Carburetor Size: The venturi is where the air mixes with gasoline. It is also where the air passage gets narrower, to cause a higher air speed in order to atomize or break up the liquid fuel into smaller droplets. With Dellorto SHA carburetors, two numbers are used to describe the size of the venturi. The first number is the venturi exit, and the second number is the venturi entrance. So looking at an SHA 14/12 from the front you see a 12mm hole, and from the back (engine side) you see a 14mm hole.

Choke Type: The choke is a lever you push or pull, “on” for cold starting, or “off” for normal running. There are three types used on Dellorto SHA carburetors:

A  direct lever  push down lever on carb to put choke “on”, give full throttle to release it “off”
B  linkage lever  same operation as direct lever
C  cable choke  cable goes to a handlebar thumb lever, pull to put choke “on”, let go for “off”    

Cable choke is needed when the carburetor choke lever cannot be reached by hand.

 


Original Carburetors

Originals          choke  approx. clamp  xxx   fits on
  ID #   size       type xxyears    size  sleeve intake  stock jets  applications

SHA 14/9      A lever  1960-90  20   20-16 16.00  44, 46, 48  20-25mph
SHA 14/9      A lever  1960-90  20   20-18 18.00  same

SHA 14/12
    A lever  1960-90  20   20-16 16.00  48, 50, 52  25-30mph
SHA 14/12    A lever  1960-90  20   20-18 18.00  same
SHA 12/12    A lever  1970-85  20   20-18 18.00  50, 52, 54  ’75-86 Derbi
SHA 12/12C cable  1980-90  20   20-18 18.00  50, 52, 54  ’86-90 Derbi
SHA 14/12P
 B linkage  ’85-on  21   21-18 18.00  00, 51, 53  ’86-06 Tomos

 


Replacement Carburetors

SHA 14/12L lever choke, 57 jet, air cover #39
replaces carbs that clamp to 16, 17, 18 or 19 mm intake pipes
$78 with 21 x 16 sleeve  some SHA 14/9, 14/12 
$78 with 21 x 17 sleeve  
$75 with 21 x 18 sleeve  14/12P, Arbeo 12/12, some SHA 14/9, 14/12
$78 with 21 x 19 sleeve

 

SHA 14/12R cable choke, 54 jet 
N/A has 19 mm clamp  replaces Gurtner Motobecane side-mount

 

 

 

SHA 15/15L lever choke, 68 jet, air cover #39
replaces carbs that clamp to 16, 17, 18 or 19 mm intake pipes
N/A with 21 x 16 sleeve  
N/A with 21 x 17 sleeve  
N/A with 21 x 18 sleeve  14/12P, Arbeo 12/12, some SHA 14/12
N/A with 21 x 19 sleeve

 

SHA 15/15C cable choke, 70 jet, air cover #39
replaces carbs that clamp to 16, 17, 18 or 19 mm intake pipes
$80 with 21 x 16 sleeve  
$80 with 21 x 17 sleeve  
$80 with 21 x 18 sleeve  Arbeo 12/12C 
$75 with 21 x 19 sleeve

 

 

 

Clamp size: These new replacement carburetors only clamp tight when the intake pipe is exactly the right size. Many intakes are made slightly smaller or become smaller from wear. When the clamp screw is tightened fully, the carburetor can still move, and eventually slip off. For a 18 sleeve, a 18.00 to 18.10 pipe would clamp tight, but 17.95 or less pipe would not clamp tight. That is not very much forgiveness.

Cut up a can: A strip cut out from an aluminum can, with scissors, can be placed under the sleeve. Thickness is 0.1mm. Either a 1/3 circle or a full circle can be used, as needed. A full circle adds 0.2 to the clamp diameter, for a 17.80 to become 18.00. A 1/3 circle adds 0.1 mm, for a 17.90 to become 18.00. A thin aluminum baking pan is thinner than a can. A thinner full circle is better for when only a little is needed.

Most brand new original Garelli, Minarelli, and Tomos intake manifolds (pipes) are 18.00. But some are 17.95, and actually need a 1/3 strip of aluminum can inserted in order to clamp tight and proper, with new original carburetors.

Cable pipes are for redirecting the throttle cable. Pipe thread is M6-0.75. Adjuster thread is M5-0.75. A throttle cable end can pass through, except 2d. Bikes with front carburetors don’t need them, because the cable goes straight up. Others have gas tanks or floor boards that the cable must go under or around.

 

 


                 P A R T S    L I S T

price colors mean used  new  new
part# colors mean old Dellorto, Dellorto, Minarelli, Garelli, Tomos, other

pic#   part#   price      description           specification


Although some pipes are shown with adjusters, bare cable pipes do not include #3a pipe adjuster and #3 pipe lock nut.

1     1476-06  rubber boot long
1
a 
  1476A $2.00 rubber boot short 219624
2     1104-37 $5.00 carb top adjuster with nut A13 M6-0.75
2a   7423-35 $13.0 cable pipe bare Vespa x  22×30 90º use 2ar
2ar 7423-re $6.00 cable pipe bare Vespa xx 22×30 90º 
2b   3698-35 N/A    cable pipe bare  6560 xx 20×28 90º use 2br
2br 3698- re $16.0 cable pipe bare Min 656  20×30 90º

2c   3600-35 $13.0 cable pipe bare  6680 xx long 70º use 2cr
2cr   243152 $8.00 cable pipe bare Tom A55 long 70º 

2d   0pipe2d $7.00 cable pipe bare Derbi  xx long 70º no adj.
280210400$7.00 cable pipe bare Garelli x  medium 35º 
2f 163515835$15.0 cable pipe bare Gar. VIP  short 45º
2g   0 pipe2g $5.00 cable pipe bare xx xxxxx 30×27 90º 
2h    219623 $5.00 cable pipe bare Tom A35 med. 70º 
2j     0pipe2j $5.00 cable pipe bare xxxxxx   med. 32º 
2k   0010854
N/A    cable pipe bare xxxxxx   long 50º 
2n    0pipe2n N/A    cable pipe bare xxxxxx   long 40º

2as  53036 $9.00 cable pipe set xxxxxxx  1+2ar+3a
2cs  53037 $14.0
cable pipe set xxxxxxxx 1+2h+2cr+3a
2ks  53038 N/A
     cable pipe set xxxxxxx  1 +2k+3a 
2js  0 53073 N/A
     cable pipe set xxxxxxx 1a+2j+3a  
2
gs    53040 $9.00 cable pipe set 11630cu 1+2g+3a 
2fs   265146 N/A
    cable pipe set Malossi  1a+2fr     
2ns  53058 N/A
     cable pipe set xxxxxxx 2n+3b      
3     1691-27 $3.00 cable pipe lock nut M6-0.75  special

12 12a 12b slides #1 #2 #12 and others

3a    219625 $6.00 pipe adjuster with nut M5-0.75 not M5-0.8
3b   1692-27 $3.00 pipe adjuster lock nut M5-0.75 not M5-0.8
4
     3318-36 $2.00 top screw M4-0.75 x 14 slot not M4-0.7
5     5011-23 $1.50 narrow washer M4 
     06110M $5.00 top bare metal  6320
6a   6110-53 $5.00 top bare white plastic
6   00-6110 N/A    top bare black plastic
6c     219596 $16.0 top bare black angled hole 30° 85-06 Tomos
6  topass6d $15.0 top assy metal   6+7+8+9+10
6  topass6e $15.0 top assy white  6a+7+8+9+10
6f    0-13662 N/A     top assy black  6b+7+8+9+10
7     6115-22 $2.00 hinge pin (in top) 6510
8     6259-61 $2.00 spring choke (in top) 6460
9     6112-26 $5.00 lever choke trigger 6450
10   6111-30 $3.00 gasket for carb top 6410
11   3346-61 $10.0 spring throttle return 6480
12   6108/64 $12.0 slide throttle #1 metal 219580 6590 25mph
12a 6108/2x $8.00 slide throttle #2 metal 20mph
12b 00-6108 N/A     slide throttle #12 plastic
13   4190-36 $5.00 screw 6620 M5-0.75 x 15 not regular metric
14   3385-30 $1.00 seal washer 5 x 9 for metal banjo not plastic
15   6106-00 $8.00 banjo metal angled out 6530 3/16″

15a  219584 $9.00 banjo inlet metal straight 3/16″
15b 00-9249 $7.00 banjo plastic angled out 6535 3/16″
15c Derb15b N/A     banjo inlet thick 1/4″ put a thin hose over 15a
16   6109-29 $5.00 filter fuel plastic mesh 6360
17   6304-27 $2.50 nut M6 teardrop 6350 most have regular nut
18   6159-30 $3.00 gasket for air filter 6420
19   6105-00 $3.00 spring for choke plate 6470
20   6112-26 $7.00 choke plate-lever short  type A lever choke
20a 6114-64 $7.00 choke plate-lever medium 6570
20b 8026-50 $7.00 choke plate-lever long  6580  Cimatti type
21   5417-22 $3.00 pivot step-bolt choke 6520
22   8773-22 $2.00 hinge pin 6500 Ø2.0 x 16.5 
23a 0-14148 $7.00 21-16 sleeve, inner lip for 16.00 mm intakes
23b 0-12914 $7.00 21-17 sleeve, inner lip for 17.00 MB (some)

23c 0-10811 $7.00 21-18 sleeve, inner lip for 18.00 mm intakes

23d 0-11362 $7.00 21-18 sleeve, outer lip for 18.00 mm intakes
23e 227324 $5.00 rubber ring,  for 23d  21 x 16 x 3.5 angled
23e -227324 $5.00 only for carbs that have sleeve 23d Tomos
23f  0-10146 $7.00 21-19 sleeve, inner lip for 19.00 Peugeot, MB
23g 2300-62 $7.00 21-19 sleeve, outer lip for 19.00 Peugeot, MB

23h 6124-62 $5.00 20-16 sleeve, inner lip for 16.00 Morini MO1,
23h continued  Demm, Benelli G2, Tomos ’74-85, Batavus M48
23i  6448-62 $7.00 20-18 sleeve, inner lip for 18.00 Minarelli V1,
23i  continued  Garelli, Tomos ’85-06, Morini M1

23j 00 19-17 $22.0 19-17 sleeve,
inner lip for Motobecane (some)
23k114482 $12.0 18-16 sleeve, inner lip for Vespa type SHA

24   6305-36 $2.00 clamp bolt M6-1.00   
25   6140-37 $4.00 idle screw M4-0.70 x 25 regular metric !
26   3606-61 $2.00 spring idle Ø4 Ø6 x 12  
27   2838-05 $10.0 float needle valve L=17.0 photo
28   1486/42 $5.00 jet 42 0.0178″=0.451  M5-0.75 thread (all)
28   1486/43 none   jet 43 0.0182″=0.462 pre-78 Ciao & Bravo
28   1486/44 $5.00 jet 44 0.0186″=0.472
28   1486/45 none   jet 45 0.0190″=0.483 78-on Ciao & Bravo
28   1486/46 $5.00 jet 46 0.0194″=0.493
28   1486/47 $7.00 jet 47 0.0198″=0.503
28   1486/48 $5.00 jet 48 0.0202″=0.513 most 20mph mopeds
28   1486/49 $7.00 jet 49 0.0207″=0.525 78-on Vespa Grande
28   1486/50 $5.00 jet 50 0.0210″=0.533 76-80 Garelli (some)
28   1486/51 $7.00 jet 51 0.0215″=0.546 85-91 Tomos late A3
28   1486/52 $5.00 jet 52 0.0219″=0.556 most 30mph mopeds
28   1486/53 $7.00 jet 53 0.0223″=0.566 92-95 Tomos early A35
28   1486/54 $5.00 jet 54 0.0227″=0.577 86-90 Derbi (flat reed)
28   1486/55 none   jet 55 0.0231″=0.587
28   1486/56 $5.00 jet 56 0.0235″=0.597 96-06 Tomos late A35
28   1486/58 $5.00 jet 58 0.0242″=0.615
28   1486/60 $5.00 jet 60 0.0247″=0.627 96-06 Tomos+exhaust
28   1486/62 none   jet 62 0.0255″=0.648
28   1486/64 none   jet 64 0.0262″=0.665
28   1486/66 none   jet 66 0.0268″=0.681
28   1486/68 none   jet 68 0.0274″=0.696
28   1486/70 none   jet 70 0.0280″=0.711
29   6122-80 $18.0 float all white plastic
30   612300 $2.00 gasket rubber ring all new ones are round
31   6107-96 $5.00 float bowl metal
31   0 13412 $5.00 float bowl plastic          
32   3598-36 $4.00 screw M4-0.75 x 18  not regular metric
33   4611-50 $4.00 clamp w/nut M4-0.75 
34   4617-36 N/A     screw M4-0.75 x 25 re-thread nut to use #8-32
35   6117-86 $9.00 air filter metal screen
36   7758-85 $10.0 air box small thin type 1 no tubes 40
37   8603-85 $11.0 air box large thick type 5 no tubes 41
37  
8605-85 $12    air box large thick type 3 not shown
38   5660M   $15.0 air box Minarelli type black new Malossi
38  005660   $25.0 air box Minarelli type gray used original
39   0-53051 $17.0 air cap, clip and screen set
39a  53051a $10.0 air cap only
39b  53051b $6.00 clip only
40   7195-35 $7.00 restrictor tube small Ø8×20
41   5309-35 $8.00 restrictor tube large Ø9×50   
42  6090813 $22.0 air filter aftermarket  this needs a bigger jet

39b clip, 39a air cap

43C  53057   $8.00 cable choke plate set type C  43a+43b+21
43a  plate43  $6.00 cable choke plate only  type C
43b spring43 $3.00 cable choke spring only
44B  223025 $7.00 pivot shaft w/linkage  type B, gets rounded
45B  223027 $2.00 spring for pivot shaft  type B 
46B  223026 N/A     choke plate xxxxxxx type B
47B  223028 $7.00 choke lever external B, gets hourglass-shaped
48B  031930 $1.00 lock washer M4  B, better to weld 46,47,49
49B  031073 $1.00 nut M4-0.70      B, better to weld 46,47,49

42 compact air filter
Fits 1996-06 Tomos

50   g-set50 $6.00 gasket set for y’all  10, 14, 30
51  0-52533 $10.0 gasket set pre-’85  10, 14, 30, 18, 18, 1a, 55, 56
51  0-52533 $10.0 for older SHA pre-1985 with 20mm clamp size

52  0-52579 $12.0 gasket set post-85 10, 14, 30, 18, 23e, 23e, 57
52  0-52579 $12.0 for newer SHA 1985-on with 21mm clamp size

55  0-ring55 $2.00 square rubber ring 14 x 20 x 2.0 for some pre-85
55  0-ring55 $2.00 only for 20mm intakes (when no sleeve is installed)

56  0-ring56 $1.00 tiny rubber o-ring  3 x 6.5 x 1.75 only for  ?
57  0-ring57 $2.00 square rubber ring 15 x 21 x 2.0 for some post-85
57  0-ring57 $2.00 only for 21mm intakes (when no sleeve is installed)

50, 51, 52 Dellorto SHA gasket sets (guarnizioni)

Dellorto SHA choke levers

 

 

 

 

 

 

 

 

 

Tomos Parts
51 219374 $10.0 junction sleeve replica center mount 85-95 A3+A35
52 219373 $19.0 air box bare (silencer) xxxx   85-95 A3+A35
53 214330 $12.0 inlet tube Ø12.5×60 straight 85-91 A3 (pre-85 with Encarwi was Ø9)
53 223606 $9.00 inlet tube Ø12.5×110 curved 92-95 A35


55 229705 $14.0 junction sleeve side mount x  96-06 A35
56 229706 $2.50 inlet grommet xxxxxxxxxxxx 96-06 A35
57 229769 $35.0 air box assy 57, 58, 59 xxxx 96-06 A35
58 044438 $1.00 air box screw xxxxxxxxxxxxx 96-06 A35
59 229704 $7.00  air filter foam xxxxxxxxxxxx  96-06 A35

60 025195 $0.60 intake screw M6x30 hex xxx  85-91 A3
61 026289 $0.50 intake screw M6x18 hex xxx  85-91 A3
62 031932 $0.20 washer M6 xxxxxxxxxxxxxx   85-91 A3
63 219371 $15.0 center intake A3 xxxxxxxxxx  85-91 A3
63 219564 $18.0 center intake A3 (oil inject)    85-91 A3
64 219372 $5.00 intake gasket thin xxxxxxxx   85-91 A3

65 026566 $1.50 intake screw M5x20 allen xx  92-95 A35
66 031931 $0.20 washer 5mm xxxxxxxxxxxxx  92-95 A35
67 227592 N/A     center intake A35 (oil inject)  92-95 A35
68 223748 $3.00 reed valve gasket xxxxxxxxx  92-06 A35
69 222238 $34.0 reed valve 2-petal xxxxxxxx   92-06 A35
70 229707 N/A     side intake (no oil inject.) xx  96-06 A35
71 229716 $21.0 side intake (oil injection) xxx  96-06 A35

An oil-injection intake has a M6-threaded hole for the oil line. A no-oil injection intake does not.
Plug the hole with a M6x8 bolt and M6 seal washer, to convert oil-injection to no oil injection. 

 

 

 

 


Encarwi Carburetors

October 25, 2014

encarwiContents:   1. Encarwi “Tomos”   2. Encarwi “Batavus”   3. Encarwi “Trac”

               4. Encarwi Jets   5. Encarwi Info   6. Encarwi “Early”  7. Bing Jets

 


Encarwi Tomos1. ENCARWI A83, 88A85/102, 88A85/103

– Used on 1976-83 Tomos A3 mopeds.
– Located above engine, difficult to remove.
– Serviceable from sides.
– No choke cable. Choke is part of throttle.
 

Pic  Number   Description           Price   Remarks 
a 209070 carburetor A8300/000 N/A  Ø12 1976-83
b 000000 carburetor 88A85/102 N/A  Ø12 1980-84
c 000000 carburetor 88A85/103 N/A  Ø12 1984-85
1   209116 short 3.5 jet #46       $18.0 =0.445
1e encl46   long  3.5 jet #46       $15.0 =0.445
2   206765b l-holder for short jet $41 see below
2e 206765e l-holder for  long jet $20 see below
3   209118  slide Ø14 426 w/hole $18 auto-choke
4   209003  spring Ø9.5 x 42        $5
5   206763  carb top screw-on    $24 M18x1 thread
11  206770 float with needle       $35 used only
12  206772 float top with seat     $25 new
13  206771 gasket for float top   $6
14  206773 banjo black plastic    $15 breaks easy
14  mbanjo banjo metal upgrade $12.0 w/2 washers 
16  206775 banjo bolt               $7.00
17  206774 fuel filter all metal    $15.0 clean & reuse
18  027053 screw M4 x 10 slot  $1.30
20  027079 clamp bolt                  $5
24  200384 air filter metal mesh    none...0
25  209215 air box (silencer)        $20
26  209216 junction sleeve rubber N/A gets hard
27  209217 inlet tube connector     $3
28  209579 inlet tube (not shown)  $3
30  200382 intake gasket thick      $8
32  217315 intake manifold oil inj  N/A w/M6x1 hole
33  209085 intake manifold          $22 OD 16, ID 12
34  031932 lock washer M6       $0.25
35  044284 hex bolt M6 x 22     $1.00

Encarwi Tomos Carbs

Left, 1974-83 Tomos carb, Encarwi A83, bare.
The jet and jet holder unscrew from the side hole.
The jet can be cleaned out easy, on the roadside.
Right, 84-86 Tomos, Encarwi 88A85/103, complete.
The side hole is blocked. Jet access is from bottom.
The engine must be lowered to access the jet.
Jetting/servicing is ten times more difficult.

 

 

 

 

 

 

Encarwi 88A85/103

At right is a 88A85/103 with the non-removeable jet-holder-spray-tube removed. The jet is a 4mm thread, not 3.5 like all the other Encarwi jets. This one was not a tight fit and needed epoxy to hold it. When the jet was unscrewed the whole brass tube turned.

 

 


Encarwi Batavus2. ENCARWI  S8A, S23, S22, S25, 88S25/101

– Original on Laura M48 engine
– Used on 1976-79 Batavus, 1977-78 Badger.
– Located behind and below engine
– Needs longer throttle and choke cables.
 

Pic# Number   Description             Price   Version
a   487180  carburetor S22 (Ø12)    N/A 30mph
      56 jet, Ø14 slide 405, Ø16 air inlet
b   541780  carburetor S25 (Ø12)    N/A 30mph
      56 jet, Ø14 slide 167, Ø16 air inlet
c   481790  carburetor S8A (Ø8 )    N/A 25mph
      52 jet, Ø14 slide 190, Ø14 air inlet
d   486795  carburetor S23A (Ø8)   N/A 20mph
      50 jet, Ø14 slide 190, Ø14 air inlet
e   5417xx  carb 88S25/101 (Ø12)   N/A 30mph
      56 jet, Ø14 slide 188, Ø16 air inlet
1a 541729 orig short jet #56=0.523   none 30mph
1a 335200 generic short #52=0.520 $4.00
subst.
1b 335000 generic short #50=0.500 $4.00
1c 334900 generic short #49=0.490   none
subst.
1c 481727 orig short jet #52=0.493 $5.00
25mph
1d 334800 generic short #48=0.480 $4.00
subst.

1d 481726 orig short jet #50=0.478   none 20mph
2 206765b long holder for short jet $41 see below
2e 206765e long holder for long jet $20 see below
3    481758  throttle slide #405    N/A S22 30mph
3a  561742  throttle slide #167    $35 S25 30mph
3b  5617xx  throttle slide #188    N/A 88S25/101 
3c  486723  throttle slide #190    $25 25 & 20mph
4    209003  spring Ø9.5 x 42        $5
5    206763  carb top screw-on    $24 M18x1 thread
   481746  idle screw M4-0.7    $12 can use M4
10  481747  spring Ø4.6,Ø6.6 x 9  $3
11  206770  float with needle         $35 used only
12  206772  float top with seat      $25
13  206771  gasket for float top    $6
14  206773  banjo black plastic     $15
14  mbanjo  banjo metal upgrade $12.0 w/2 washers 
16  206775  banjo bolt               $7.00
17  206774  fuel filter                  $15.0
18  027053  screw M4 x 10 slot  $1.30

Left 1970’s original float, right 90’s replacement

20  481724  clamp bolt                  $5
21  481743  choke plate                 $7
22  481745  bolt choke pivot          $3
23  481744  spring choke               $3
24  200384  air filter metal mesh    none...0
25a481713  air box (inlet 16mm)  N/A 30mph
25b481734  air box (inlet 14mm) N/A 25 & 20mph
26  481733  rubber band              N/A
27  481735  wire clip                     $8
28a481793  intake tube 16 id    N/A  30mph
28b486781  intake tube 14 id    $5  25 & 20mph

 
 
 
 
 
 
 
 

3. ENCARWI H12, H8 CARBURETORS

– Made special for Laura M56 engine.
– Serviceable without removal.
– Used on 1978-80 Batavus Regency (M56)
– 1981-85 Trac Clipper, Eagle, Hawk (M56)
 

  1 561782 $220. carburetor H12 (30 and 25mph)
  1 56xxxx $000.  Ø12 with #56 jet
  1 561787  N/A    carburetor H8 (20mph version)
  1 56xxxx $000.  Ø8 with #46 jet
1a 1 565756   none orig. short jet #56 =0.523 mm
1a 1 335200 $4.00 generic short jet 52 =0.518 mm
ae 1 encm56 $12.0 orig. med. jet #56 =0.523 mm
1b 1 209116 $18.0orig. short jet #46 =0.445 mm
be 1 encm46  N/A    orig medium jet 46 =0.445 mm
2a 1 491722 $40.0 short holder for s. jet see below
2e 1 491722 $30.0 short holder for m. jet see below
3   1 561748 $25.0 slide throttle Ø14 (H12) #3
3a 1 561742  N/A    slide throttle Ø12? (H8)
4   1 481759 $10.0 spring throttle Ø9.5 x 44
  1 561721 $25.0 carb top white plastic
6   1 046430 $7.00 rubber cover over carb top
  1 481739 $0.50 screw M5 x 15 slot
9   1 206770 $35.0 float with needle, good-used
10206772 $25.0 float top with seat
11206771 $6.00 gasket for float top
12mbanjo $12.0 banjo metal with 2 washers
13 2 swash8 $1.00 banjo seal washer 8mm
14206775 $7.00 banjo bolt
15206774 $15.0 fuel filter
16027053 $1.30 screw M4 x 10 slot
18 1 561740 $5.00 idle screw M5-0.80 x 16
19481747 $2.00 spring idle screw Ø5,Ø7 x 10
20561743  N/A    choke slide
21561745 $2.00 o-ring for choke 1 x 4.0
22561747  choke cable wire
23491724 $8.00 spring choke return
25561795  N/A    air box with filter good used
26823514 $0.60 screw M5 x 30 phillips
27561714  N/A    air filter screen
28 1 561713 $5.00 air filter foam strip

 

Encarwi H12 carb on Trac M56 engine

Encarwi H12, with no top, on Trac M56 engine

 


4.  ENCARWI  JETS

 

Encarwi Jets: Most Encarwi carburetors use standard Bing 3.5mm jets. Those jets have a “short” head that is only 3mm long. To use a short jet, the jet holder must be for a short jet. But some Encarwi carburetors have longer 3.5mm jets with 8mm “medium” or 12mm “long” heads.

Encarwi “medium” jets for Laura M56
encm56  size 56   $12  thread=3.5 head=8

Encarwi “long” jets Laura M48, Tomos A3
2  encl45  size 45   $12  thread=3.5 head=12
2  encl46  size 46   $15  thread=3.5 head=12
2  encl52  size 52   N/A  thread=3.5 head=12
2  encl56  size 56   N/A  thread=3.5 head=12
2  encl58  size 58   $$7  thread=3.5 head=12

 

Encarwi jet holders
 206765b long jet holder for short (Bing) jet         $25
2  206765e long jet holder for long Encarwi jet         $20 can be a substitute for 3
 491722e short jet holder for medium Encarwi jet  $30
4  491722b short jet holder for short (Bing) jet         $40

 


5. Encarwi Info

1971-1977 Tomos Automatic N had a Laura M48 engine with an Encarwi carb

Before 1973, Tomos had Puch and Laura engines. The 1971 Tomos Automatic N had a Laura M48 engine with Encarwi carburetor. Tomos continued to use Encarwi on their A3 engine, until 1983.

1977 Flandria Bermuda with Encarwi

1977 Flandria Bermuda
Encarwi A-type carb

Welcome. Encarwi (made in Holland, now the Netherlands) was a division of Bing (Germany). On US models, Bing-Encarwi carburetors were used on mopeds by Batavus and Badger, with Laura (Holland) engines, Flandria (Belguim), and pre-1986 Tomos (Yugoslavia). 

 

 

 

Encarwi Carbs

Encarwi carbs on US models of Batavus and Tomos.
Top, S-series. Bottom, A-series (no idle screw).

 
 bing crown
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Encarwi “A” series carbs had an “automatic” choke, controlled by a special twist throttle with thumb button. The choke button lets the throttle twist opposite, below “zero”. This exposes a hole in the slide valve, in front of the fuel nozzle. After starting, twist throttle and choke clicks off automatically.  
A11            (8mm, Ø14 slide 408, jet 52-54), for 20kmh Laura M48 engine (Euro model)
A22            (8mm, Ø14 slide 108, jet 50-52), for 25kmh Laura M48 engine (Euro model)
A21          (12mm, Ø14 slide 202, jet 56-58), for 40kmh Laura M48 engine (Euro model)
A83          (12mm, Ø14 slide 426, jet 46), for 20, 25, 30mph Tomos A3 engine 1974-80+
88A85/102 (Ø12, Ø14 slide 426, jet 46) for 20, 25, 30mph Tomos A3 engine 1980-83+
88A85/103 (Ø12, Ø14 slide 426, jet 4mm #50, no jet access from side) for Tomos A3 1983-85
All of these jets have 3.5mm threads except for the 88A85/103 which has 4mm threads.
 
Encarwi “S” series carburetors had a “standard” choke, controlled by a small lever on the handlebar via a cable.
88S23A      (8mm, Ø14 slide 190, jet 54),    for 20kmh Laura M48 engine (Euro model)
S23B          (8mm, Ø14 slide 190, jet 52-54), for 25kmh Laura M48 engine (Euro model) 
S23A          (8mm, Ø14 slide 190, jet 50-52), for 20mph Laura M48 Batavus 1976-77
S8A            (8mm, Ø14 slide 190, jet 52-54), for 25mph Laura M48 Batavus 1976-77
S22          (12mm, Ø14 slide 405, jet 54-58), for 30mph Laura M48 Batavus 1976-77
S25          (12mm, Ø14 slide 167, jet 56-58), for 30mph Laura M48 Batavus 1977-78
88S25/101 (Ø12, Ø14 slide 188, jet 56-58), for 30mph Laura M48 Batavus 1978-80
 
Encarwi “H” series carburetors were designed specifically for the Laura M56 engine, later made by Trac (Daelim).
H8           (8mm, Ø12 slide ???,  jet 46), for 20mph Laura M56 eng Batavus 1978-80
H12/102 (12mm, Ø14 slide 3,  jet 56), for 25 & 30mph Laura M56 Batavus 1978-80
unmarked (12mm, Ø14 slide 3?, jet 56), 25 & 30mph M56 remake Trac 1982-85 
 
 
Encarwi carbs and slides

Top, Encarwi carburetors, engine view, with slides slightly open, showing the idle air channels or slots or holes.
Bottom, the corresponding throttle slides, all 14mm diameter, bottom view. The pair of large holes is for the cable.
Substitutions or conversions: Any S-type slide can be drilled and machined to be made for an A83 or H12 carb.
The S-type slides (190, 405, 188, 167, 2) all interchange, but have different idle mixture idling behaviors.
The Tomos A3 slide 426 fits a Trac M56 with H12 carb, with only minor widening (drilling) of the sprayer hole.

 

 

Encarwi Slides

The amazing Encarwi 426 auto-choke throttle slide (Tomos A3) is explained in four steps:
1. Full power   – throttle cable is pulled all the way. The slide does not have to be there. Main jet controls the mixture.
2. Partial power -throttle cable is pulled part way. The slide limits the amount of air. The main jet controls the mixture.
3. No power (idle) -throttle cable is pulled slightly. The slide blocks most of the air. Idle slot size controls the mixture. 
4. Cold start  – throttle cable is not pulled at all. The choke jet hole and choke air hole in slide 426 control the mixture.
Substitutions or conversions: The S25 and A83 Ø12 carbs are the same, except for the throttle slide and idle screw.
The Ø14 throttle slides 167 and 426 are nearly the same, except the Auto type 426 has extra choke holes and cut outs.

 

 

 


Encarwi Karburator from 1960's

Encarwi Carburator, from 1960’s or 70’s

6. ENCARWI “EARLY”

Carwi Karburator

Carwi Carburator, from the 1950’s

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Encarwi A30 carb

Encarwi A30 carburetor

Encarwi A30 on 1960's Flandria moped

Encarwi A30 on
1960’s Flandria

You can see that these early Encarwi carbs have many things in common with the later ones. The most obvious thing is the angle of the throttle slide with the venturi. Most carburetors have the slide valve 90 degrees to the air flow, but Encarwi carbs are more like 60 degrees. The other thing unique to Encarwi is the “automatic” choke, indicated by the absence of an idle speed adjustment screw, the choke holes and cut-away in the slide, and an extra thumb button on the throttle control that lets the throttle cable go completely slack, below normal idle or “zero”.  

 

 


Bing Jets

October 26, 2011

Bing jets are in Bing and some Encarwi carburetors.

3.5 mm thread (M3.5-0.60) Bing jets are on Puch-Bing, Solo-Bing, Kreidler-Bing, and Encarwi.

4.0 mm thread (M4.0-0.70) Bing jets are on Sachs-Bing, late 80’s AD-Bing and 90’s Korado-Bing.

Myrons Mopeds Bing Jet Sizes Chart

These jets are on other 1970’s – 80’s small engines with Bing carburetors. 

The Bing 3.5 main jets are also idle jets on some bigger Keihin carbs.

The Bing 4.0 main jets are also idle jets on some bigger Dellorto carbs

Original Bing jets are numbered wrong, in a sense. The jet number is not the millimeter size. An original Bing 54 is actually 0.51 mm, not 0.54. This was discovered this in the early 2000’s when aftermarket Bing jets came out. 200 jets were carefully measured with precise wire guages, and then plotted on the graph at right. The original jets (and the first A&R generics) form one line. All other generic jets form a different line.

Generic Bing jets are numbered correctly. The size they say is the millimeters they are. So a generic Bing 54 is actually 0.54 mm.

 

 

 

 

 

 

 

 

 

 


           Bing Jets (3.5 mm) 

 part #   maker   jet#  close to    measured size      price     applications

78drill   custom #00 =Bing48 0.016″ = #78 drill —————————————————————
3.5×44
  custom #00 =Bing46 0.0173″=0.440mm  $15.0  soldered, 78-drilled, then filed with .017 guitar string
Bing46  original #46 =Bing46
0.0175″=0.445mm  $18.0  76-83 Tomos early A3 models (30, 25, and 20mph)
3.5×45  custom #00 =Bing47 0.0177″=0.450mm  -N/A–
77drill   custom #00 =Bing48 0.018″ = #77 drill —————————————————————
3.5×46  custom #00 =Bing48 0.0181″=0.460mm  -N/A–
Bing48  original #48 =Bing48 0.0182″=0.462mm  $15.0  78-80 Puch (2-spd hi torque Ø12 carb 20mph)
3.5×47  custom #00 =Bing49 0.0185″=0.470mm  -N/A–
Bing50  original #50 =Bing50 0.0188″=0.478mm    none  76-78 Batavus (Laura M48 Ø8 carb 20mph)
3.5×48  generic #48 =Bing51 0.0190″=0.480mm  $4.00
3.5×49  custom #00 =Bing52 0.0190″=0.490mm  -N/A–

Bing52  original #52 =Bing52 0.0194″=0.493mm  $5.00  76-78 Batavus (Laura M48 Ø8 carb 25 mph)
3.5×50  generic #50 =Bing53 0.0195″=0.500mm  $4.00
76drill   custom #00 =Bing48 0.020″ = #76 drill —————————————————————

Bing54  original #54 =Bing54 0.0200″=0.508mm  $5.00  74-83 Puch (1-spd alum. cylinder, Ø12 carb 2.22, 20mph)
3.5×51  generic #51 =Bing54 0.0201″=0.510mm 

3.5×52  generic #52 =Bing55 0.0204″=0.520mm  $4.00
Bing56  original #56 =Bing56 0.0206″=0.523mm    none  77-80 Batavus M48 and M56 (30), 80-83 Trac M56 models
3.5×53  generic #53 =Bing56 0.0209″=0.531mm  
75drill   custom #00 =Bing48 0.021″ = #75 drill —————————————————————
3.5×54  generic #54 =Bing57 0.0212″=0.540mm  $4.00
Bing58  original #58 =Bing58 0.0213″=0.541mm  $7.00  78-83 Puch (2-spd hi torque cyl. Ø12 carb 2.22 30mph)
3.5×55  generic #55 =Bing59 0.0217″=0.551mm  $4.00
3.5×56  generic #56 =Bing60 0.0220″=0.561mm  $4.00
Bing60  original #60 =Bing60 0.0222″=0.564mm    none  78-83 Puch (1-spd hi torque cyl. Ø12 carb 2.22 30mph)
3.5×57  generic #57 =Bing61 0.0224″=0.571mm  $4.00
75drill   custom #00 =Bing48 0.0225″=#74 drill —————————————————————
3.5×58  generic #58 =Bing62 0.0228″=0.580mm  $4.00
Bing62  original #62 =Bing62 0.0229″=0.582mm  $7.00
3.5×59  generic #59 =Bing63 0.0232″=0.591mm  $4.00

Bing64  original #64 =Bing64 0.0234″=0.594mm  $6.00  74-83 Puch (1-spd al cyl Ø14 carb 2.22 needle jet 30mph)
3.5×60  generic #60 =Bing64 0.0235″=0.600mm  $4.00
Bing66  original #66 =Bing66 0.0239″=0.607mm    none
75drill   custom #00 =Bing48 0.024″ = #73 drill
—————————————————————
3.5×61  generic #61 =Bing65 0.0240″=0.610mm  $4.00

3.5×62  generic #62 =Bing66 0.0244″=0.620mm  $4.00
Bing68  original #68 =Bing68 0.0248″=0.630mm   none   78 Sears (1s al cyl Ø14 carb 30mph), Kreidler (30mph)
3.5×63  generic #63 =Bing68 0.0248″=0.630mm  $4.00
75drill   custom #00 =Bing48 0.025″ = #72 drill
—————————————————————
3.5×64  generic #64 =Bing69 0.0252″=0.640mm  $4.00

Bing70  original #70 =Bing70 0.0254″=0.645mm    N/A   84-86 Puch Cobra (Ø14 carb, 2.17 needle jet 25mph)
3.5×65  generic #65 =Bing71 0.0256″=0.650mm  $4.00
75drill   custom #00 =Bing48 0.026″ = #71 drill
—————————————————————
3.5×66  generic #66 =Bing72 0.0260″=0.660mm  $4.00

Bing72  original #72 =Bing72 0.0260″=0.660mm    N/A   84-86 Puchs had bigger main jets, but smaller needle jets.
3.5×67  generic #67 =Bing73 0.0264″=0.670mm  $4.00

Bing74  original #74 =Bing74 0.0267″=0.678mm    N/A   1990’s Puch remakes also had 70’s jets, 2.17 needle jets.
3.5×68  generic #68 =Bing74 0.0268″=0.681mm  $4.00
3.5×69  generic #69 =Bing75 0.0272″=0.690mm  $4.00

Bing76  original #76 =Bing76 0.0273″=0.693mm  $6.00
3.5×70  generic #70 =Bing77 0.0278″=0.705mm  $4.00
75drill   custom #00 =Bing48 0.028″ = #70 drill
—————————————————————
3.5×71  generic #71 =Bing78 0.0280″=0.715mm  -N/A--

Bing78  original #78 =Bing78 0.0280″=0.711mm    N/A
3.5×72  generic #72 =Bing79 0.0283″=0.725mm  $4.00

Bing80  original #80 =Bing80 0.0287″=0.729mm    N/A
3.5×73  generic #73 =Bing81 0.0287″=0.735mm    none
3.5×74  generic #74 =Bing82 0.0291″=0.745mm  $4.00

75drill   custom #00 =Bing48 0.0292″ = #69 drill —————————————————————
Bing82  original #82 =Bing82 0.0292″=0.742mm  $7.00 2000’s Bing Ø15 carb with smaller 2.17 needle jet
3.5×75  generic #75 =Bing83 0.0296″=0.755mm    none
Bing84  original #84 =Bing84 0.0300″=0.762mm    none 1978-79 Puch Magnum X

 


cleaning a #25 jet

       Bing Jets (4.0 mm) 

At right, the smallest of the small. The #25 pilot jet is bigger than wire wheel wires, but smaller than wire brush wires in the background. It’s three hairs wide!

part number  maker  jet#  close to    measured size      price     applications

Tomos243222 Dell.  #25 =Bing27 0.0107″=0.272mm     $8  Tomos A55 pilot (idle) jet
Tomos243110 Dell.  #29 =Bing31 0.0124″=0.314mm     $8   same as Tomos #25 idle jet “cleaned” with #80 drill
D1486-030 Dellorto #30 =Bing33 0.0128″=0.325mm     $8  good for A55 pilot jet, mix screw 1 turn more out
77drill   custom #00 =Bing48 0.0135″ = #80 drill —————————————————————

D1486-032 Dellorto #32 =Bing35 0.014″ = 0.355mm     $8  same as drilled with #80 drill, sub for A55 pilot jet
77drill   custom #00 =Bing48 0.0145″ = #79 drill —————————————————————

D1486-035 Dellorto #35 =Bing39 0.0149″=0.378mm    N/A
77drill   custom #00 =Bing48 0.016″ = #78 drill —————————————————————

D1486-040 Dellorto #40 =Bing45 0.0170″=0.431mm     $8
4mBing45 Bing orig #45 =Bing45 0.0171″=0.434mm    N/A   Sachs 504/1A DK (19mph)
77drill   custom #00 =Bing48 0.018″ = #77 drill —————————————————————
4mBing48 Bing orig #48 =Bing48 0.018″ = 0.46mm      $8
D1486-043 Dellorto #43 =Bing49 0.0182″=0.462mm    N/A
4mBing50 Bing orig #50 =Bing50 0.0183″=0.465mm     $8  Sachs 504/1B and 505/1B (Ø10 carb 20mph)
D1486-044 Dellorto #44 =Bing51 0.0187″=0.475mm    N/A
4.0×48 000 generic #48 =Bing51 0.0189″=0.480mm
D1486-045 Dellorto #45 =Bing51 0.0190″=0.483mm     $8
4mBing52 Bing orig #52 =Bing52 0.0194″=0.493mm    $8.00 Sachs 504/1A and 505/1A (Ø12 carb 30mph)
D1486-046 Dellorto #46 =Bing52 0.0194″=0.493mm    N/A
4.0×50 000 generic #50 =Bing53 0.0197″=0.500mm
76drill   custom #00 =Bing48 0.020″ = #76 drill —————————————————————

4mBing54 Bing orig #54 =Bing54 0.0200″=0.508mm    $8  ’84-86 Puch Austro Daimler (30mph)

D1486-047 Dellorto #47 =Bing54 0.0198″=0.503mm    N/A
D1486-048 Dellorto #48 =Bing55 0.0202″=0.513mm    $8  Sachs 504/1A and 505/1A (without air filter box)
4.0×52 000 generic #52 =Bing56 0.0205″=0.520mm
4mBing56 Bing orig #56 =Bing56 0.0206″=0.523mm    N/A  

D1486-049 Dellorto #49 =Bing56 0.0207″=0.526mm    N/A
75drill   custom #00 =Bing48 0.021″ = #75 drill —————————————————————

D1486-050 Dellorto #50 =Bing57 0.0210″=0.533mm    N/A
4.0×54 000 generic #54 =Bing58 0.0212″=0.540mm
4mBing58 Bing orig #58 =Bing58 0.0213″=0.541mm   $8.00 Sachs 504/1D and 505/1D (Ø12 D-carb 30mph)
D1486-051 Dellorto #51 =Bing59 0.0215″=0.546mm    N/A
4.0×56 000 generic #56 =Bing51 0.0220″=0.560mm
75drill   custom #00 =Bing48 0.0225″=#74 drill —————————————————————

D1486-055 Dellorto #55 =Bing63 0.0230″=0.580mm     $8
4.0×58 000 generic #58 =Bing63 0.0230″=0.580mm
4.0×60 000 generic #60 =Bing65 0.0236″=0.600mm
75drill   custom #00 =Bing48 0.024″ = #73 drill —————————————————————

4.0×62 000 generic #62 =Bing68 0.0244″=0.620mm

D1486-060 Dellorto #60 =Bing69 0.0250″=0.635mm     $8

 

 

 


Encarwi Carburetor Service

May 4, 2008

Encarwi A83 carburetor on Tomos A3 engine

Encarwi Carb Service for Tomos A3 1974-83

This very simple, early Tomos carb is designed to be serviced without removal. After 1985, Tomos A3 & A35 models came with Dellorto SHA14/12 carburetors. The Tomos A3 carburetor is in a confined area above the engine and below the sheet metal gas tank/frame. It is difficult to remove.

 Two super usfeul and easy checks:

1) Check the jet. With a large flat head screwdriver or a 9mm wrench, remove the jet holder #2. Remove the jet #2 with a medium-thin flat head screwdriver. Hold the jet up to a light source, such as a sunny white wall. Look through the tiny hole to see if light gets through. If it’s pitch black it’s completely blocked. If it’s not circular then it’s partially blocked, like by a fiber.

2) Check everything else. When the jet holder is removed, and the gas valve is turned on, gasoline should flow out of the gas tank, through the banjo bolt #16 at the float top #12, and then dribble out the hole where the jet holder was. This is a way to quickly test the fuel system, tank, valve, line, filter, and float, all at once.

If gas does not spill out with the jet holder removed, then gas is not getting to the jet. Check if gas comes out of the tank. If gas is getting to the carburetor, but not getting to the jet, then either the inlet banjo #14 or banjo bolt #16 is clogged, or the float top #12 is clogged, or the float #11 is in upside down, or the float is stuck in the up position. Several things can cause this kind of float to stay up and not drop down and let gas come into the float bowl reservoir: being installed upside down (pointy end goes up), rust powder filling up the guide hole at the bottom of the float chamber, the float bulb being pushed too far down the rod, the wrong float, or a dented float chamber wall.

 

 

Encarwi Batavus

Encarwi S25 carburetor on Batavus M48 engine

Servicing

The jet holder #2 unscrews from the left side. It holds the jet #1, Bing 3.5mm size 46.

To remove an old, hard, shrunken and very stuck on, fuel hose, be careful not to break off the “neck of the banjo”. That means you only pull straight out and rotate, never pull or twist sideways. If that fails, a diagonal pliers aka dikes aka wire cutters, can be used to cut the old fuel line, parallel to the hose, without cutting the banjo underneath. The cut does not need to go all the way through the old fuel hose, but far enough to weaken it.   

To service the float, loosen the clamp screw #20 and rotate the carb so it is tipped to the right. Remove the 11mm hex head banjo bolt. Remove the two slot head screws #18. Lift off the float top. Lift out the float with your fingers. It should lift out freely and not feel stuck.

Float versions, left 70’s bulb, right 90’s solid

 

 

 

 

 

 

 

 

 

 

 

Encarwi S12 carburetor on Trac M56 engine

Things that cause not enough gas:

Rust powder filling up the guide hole at the bottom of the float chamber. Remedy is twisting a correct size drill bit with your fingers, to pull the powder up and out of the hole. With the jet holder removed and the gas valve turned on, gasoline should flow out of the tank, through the float valve, and spill out the jet holder hole. The amount should be enough to fill the float reservoir in a few seconds, which is roughly a spoonful every 4 seconds.

The bulb being pushed too far down the rod. Remedy is to push it back up. See the above photo with measurements.

Dented float chamber wall. Remedy is to grind or sand down the high spot.

Blocked float reservoir air vent. Gasoline cannot come in unless air can get out. Remedy is to find where it is blocked at, and remove the blockage. The vent follows a channel in the back mounting surface. An empty float reservoir should fill up in a few seconds after the gas valve is turned on. To test for a blocked air vent, first empty the reservoir, then turn the gas valve on for 8 seconds and then off. Then remove the jet holder, allowing gas to dribble out, to see how much gasoline there was in the reservoir.

Blocked gas tank air vent. Gasoline cannot leave the gas tank unless air comes in. So there is a pin hole in the gas cap. When the tank is full, and the vent hole is blocked, the bike will seem to run out of gas. To test for a blocked gas cap vent hole, first fill the gas tank, then close the gas valve, then remove the fuel hose. Place a clean container under it (to check for purity and to put the gas back in the tank). Turn on the gas and observe the flow. It will flow normal at first. But in a few seconds, as negative pressure builds up, the flow will slow down and stop, if the vent is blocked. If the flow continues for 20-30 seconds (or indefinitely) then the gas tank is vented.

Things that cause too much gas:

Worn float needle tip. Remedy is to sharpen it. Examine the tip with a magnifier. Spin the float with a drill while pressing the tip gently against a sheet of emery cloth or very fine sandpaper, at the same angle, and move it slowly around to fresh parts of the sandpaper. The needle rod must be straight first. Examine the tip with a magnifier. There should be, everywhere on the cone tip, circular sanding marks, and no more circular “potholes”.

The needle is bent. Remedy is to straighten it. Normally the bend is just above the top of the bulb. It is done with just fingers and eyes. Rotate to see which way it needs to go. Bend a little. Repeat. 

The bulb being pushed too far up the rod. Remedy is to push it back down. See the above photo with measurements.

Worn float seat hole. The float valve seat is part of the float top. It is the tiny hole at the bottom of the small hole. Examine the hole with a magnifier. It should be perfectly circular and free of nicks and scratches. Polish it with a spinning tooth pick, or the stalk of a Q-tip. 

Float bulb has gasoline inside it. If the float too heavy, it won’t have enough buoyancy to stop the gasoline from getting in. Remedy is to evacuate the fuel with compressed air, locate the leak hole, and apply a minimal amount of fuel tank sealant. 

 

Servicing the M56 engine’s H12 or H8 Carburetor:

One problem unique to this carb is warping of the engine side surface. This is caused by over tightening the two mount bolts, and maybe also because the heat block behind it is semi-soft. The back side must seal not just air, for good idling, but also there is a fuel passage that can leak because of a warped carburetor body. The remedy is to grind the back side flat again, without taking too much off. In the body, there is a narrow fuel hole at the bottom of another hole, that is impossible to see directly. That hole must be checked and cleaned with carb spray and compressed air. 

The float is the same as the other carbs. The float top is the same except it has no air vent pin hole. The idea was to not let gas spill out the vent hole. Instead the vent goes to the mounting gasket, where there is a small opening to the atmosphere, higher up.

 

 

 


Bing Carburetor Service

May 3, 2008
Bing VergaserWelcome, Carb Elbows: Long and Short         Scroll Down to See Topic 
1. Exploded View and Parts Names
2. Carburetor Service Info Sheet
3. Bing Float Needles: Rubber tip and Metal tip
4. Fuel Mixture is Controlled by Five Things
 

Welcome to Myrons Bing Carburetor Service. 

Sachs Bings can have long or short cable elbows.

Puch Bings can have long or short cable elbows.

 

 

 

 

 

 

 

 

 

 

Sachs Bing Cable Elbows: Left photo above, left is the long carb elbow, used on KTM Foxi, Sparta Buddy, and most Sparta Foxi models. Right, is the short carb elbow used on other Sachs engine models. The Sachs elbows are 7mm, not 6mm threads like Puch ones. The bigger elbow allows the throttle cable small end to pass through the 6mm adjuster. So Sachs double-ended throttle cables do not come with adjusters. The adjuster stays with the elbow. Puch Bings have 6mm elbow threads, and 5mm adjuster threads, too small for the cable end to pass through. So Puch double ended throttle cables have the 5mm adjuster trapped in them.    

Puch Bing Cable Elbows: Right photo above, left is the long carb elbow, used on Maxi models, also with the black choke extension. Right, is the short carb elbow used on Magnum type models. The current aftermarket “Puch” throttle cables are made for the short carb elbow. They idle way fast if used with the long elbow, because the slide is not allowed to go fully down to idle. Myrons sells a long elbow throttle cable, for Puch Maxi, made from a modified “Puch” throttle cable. The wire needs to be about 12mm longer. The long elbow comes on Maxi type sheet metal frame models. The short elbow comes on Magnum type tube frames, such as Sears Free Spirit or JC Penney Pinto. The short elbow is so your foot does not hit it when you get on and off the bike. See the exploded view diagram below. Other Bing moped (under 15mm venturi) carburetors are the Sachs Bing, Kreidler Bing, Solo Bing, Tomos Encarwi, Batavus Encarwi, Trac Encarwi. Much bigger Bing carburetors are also on BMW, KTM, Penton, Sachs, Maico, DKW motorcycles, all made in or near Germany.

 

1. Exploded View and Parts Names

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. Carburetor Service Info Sheet

Below, the choke slide and throttle slide must be installed simultaneously. It is difficult. The throttle slide has a slot that must line up with a prong in the carb body. The top of the choke slide slides onto a deep wide notch at the bottom of the choke rod, so moving the choke rod moves the choke slide. It often gets left out or disconnected. When the choke slide is disconnected from the choke rod, the choke will be “on”, blocking off the air supply, whenever the throttle slide is down or closed. Normally when a Puch is given full throttle, the choke slide and rod are lifted all the way up until it clicks. The click is the choke rod clip #24 settling into the clip groove near the middle of the choke rod #23. When the throttle cable is not adjusted tight enough, the choke is not lifted all the way off, and it does not click until you manually reach down and pull up on the choke rod. When the throttle cable is adjusted too tight, the engine races and does not idle slow, even with the idle screw loosened all the way. See also General Carburetor Service and Jetting for how to clean and adjust carbs in general. 

 

White Flakes

These white flakes were the cause of a customer’s Puch not running. By chance a tiny spec broke off and lodged in the main jet.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3. Bing Float Needles 

All “Bing Puch Carbs” have the slotted float type float needle with a rubber cone tip, except for some of the Sears Free Spirit 1/14/163  and 1/14/164 carbs, which have a Sachs Bing type float needle that does not lock into a slot in the float and has a metal cone tip.

4. What part controls mixture depends on how much throttle opening

Slide Carburetors Diagram


Jet Drills

January 27, 2007

 

Above, a Tomos A55 idle jet (M4 thread) is physically bigger than a Puch Maxi main jet (M3.5 thread), but the hole size is much smaller. The photo shows how the #25 jet, 0.010" (ten thousandths of an inch), will allow the thinner wire of the wire wheel to pass through the hole, but not the thicker wire of the wire brush. This is a useful cleaning technique.

Above, a Tomos A55 idle jet (M4 thread) is physically bigger than a Puch Maxi main jet (M3.5 thread), but the hole size is much smaller. The photo shows how the #25 jet, 0.011″ (eleven thousandths of an inch), will allow the thinner wire of the wire wheel to pass through the hole, but not the thicker wire of the wire brush. This is a useful cleaning technique.

This will help you visualize how small these drills and jets are!

Moped main jets range from 0.018″ (#77 drill) to 0.026″ (#71 drill). 

Moped idle jets, like Tomos A55, are 0.011″ (smaller than #80).

An average human hair is 0.003″ (three thousandths of an inch).

So moped jet holes are 4 to 9 hairs wide!

Shauns well used jet drill container from the 1980's

Shaun’s well used drill container from 1987

 

Jet Drills: All through the late 1980’s and 1990’s, Shaun (at Royal Cyclery and later at Myrons Mopeds) used the USA-made jet drills to service carburetors. The drill sizes are an American wire gauge. They did not vary in size. Those 20-piece Drill Sets 61 to 80, cost $40 in 2015, $33 in 1998. and $29 in 1987. Some are in clear plastic round dome containers, and some are in conventional metal drill set boxes.

 

 

Drill Set 61-80 USA-made

Drill Set USA-made

Jet Drills made in China

Set 1 China-made

China-made Drills: In the 2000’s there were many China made tools sold in “surplus” tool stores. The China made 20-piece Drill Sets 61 to 80, sell for $7 to $10, or one fourth as much. They have an excellent blue plastic container, that only lets out one at a time. But the drill sizes are all wrong. From about 2010 to 2014, Myrons Mopeds sold these inexpensive drill sets, not knowing that the drill sizes were inexact, to say the least.

So although the China sets cost one forth as much, they only have about seven or eight different sizes, and they lack the smaller sizes below 0.4 (or sometimes 0.6) mm. Each set is different.

 

Jet Drills made in USA

Jet Drills made in USA

Set 2 China-made

Some have poorly made drills, twisted funny, bigger at the cutting end, or lumpy, varying in thickness. Some have poorly made cutting tips, so they might wander, grab and break, or not cut well.

Despite the poor quality and inexactness, the inexpensive drills are still useful for cleaning purposes, but not for measuring and maybe not for drilling. Fortunately, brass carburetor jets are the easiest thing to drill, with a drop of oil and a pilot hole already there.

 

 


Micro Drills and Wires for Sale Individually

These drills are measured at the shank (the smooth part). At the cutting edge they are 1 or 2% bigger.

These wires are steel guitar strings, cut into 5 inch lengths. 

“Metric” jets have a number that literally means hundredths of a millimeter, so a 64 jet is 0.64 mm.

Micro Drills for sale

inch   mm/#  price     moped jets that it cleans
0.011   wire     N/A Gurtner Motobecane diffuser – two idle holes (.013)
0.0135 #80  $6.00
0.0145 #79  $5.00
0.0157 0.40  $3.00 Dellorto 38 (.0162), Bing 42 (.0162)
0.016   #78  $4.00 Dellorto 40 (.0168), Bing 44 (.0167)
0.017   wire  $0.50 Dellorto 42 (.0177), Bing 46 (.0175)
0.018   #77  $3.50 Dellorto 44 (.0186), Bing 50 (.0188)
0.019   ——  $2.00 Dellorto 46 (.0194), Bing 52 (.0194)
0.0197 0.50  $2.00 Dellorto 48 (.0202), Bing 54 (.0200), “Metric” 51 (.0201)
0.0200 #76  $3.50 Dellorto 49 (.0207), Bing 56 (.0206), Gurtner 210=52 (.0210)
0.021   #75  $4.00 Dellorto 51 (.0215), Bing 58 (.0213), Gurtner 220=54 (.0220)
0.0225 #74  $5.00 Dellorto 55 (.0231), Bing 62 (.0229), Gurtner 230=56 (.0230)
0.023   ——  $2.00 Dellorto 56 (.0235), Bing 64 (.0234), Gurtner 240=58 (.0236)
0.0235 0.60  $2.00 Dellorto 58 (.0242), Bing 66 (.0239), Gurtner 245=59 (.0239)
0.0235 0.60  $1.50 Dellorto 58 (.0242), Bing 66 (.0239), Gurtner 250=60 (.0242)
0.024   #73  $3.00 Dellorto 60 (.0247), Bing 68 (.0248), “Metric” 63 (.0248)
0.025   #72  $3.50 Dellorto 62 (.0255), Bing 70 (.0254), “Metric” 65 (.0256)
0.026   #71  $4.50 Dellorto 66 (.0268), Bing 74 (.0267), “Metric” 68 (.0268)
0.0275 0.70 x N/A  Dellorto 70 (.0280), Bing 78 (.0280), “Metric” 71 (.0280)
0.028   #70  $4.00 Dellorto 72 (.0287), Bing 80 (.0287), “Metric” 73 (.0287)
0.0292 #69  $4.50 Dellorto 78 (.0306), Bing 84 (.0301), “Metric” 77 (.0303)
0.030   wire     N/A Dellorto 80 (.0312), “Metric” 79 (.0311), Gurtner K80 (.0311)
0.031   #68  $4.50 Dellorto 82 (.0318), “Metric” 81 (.0319)
0.0315 0.80  $2.00 Dellorto 84 (.0324), “Metric” 82 (.0323)
0.032   #67  $3.00 Dellorto 86 (.0331), “Metric” 84 (.0331)
0.0325  —— $2.00 Dellorto 88 (.0337), “Metric” 86 (.0339)
0.033   #66  $4.50 Dellorto 90 (.0343), “Metric” 88 (.0346)
0.034   wire     N/A “Metric” 90 (.0354)
0.035   #65  $3.00 “Metric” 92 (.0362), Gurtner MB (side mount) diffuser (.0358)
0.0354 0.90  $2.00 “Metric” 94 (.0370)
0.036   #64  $3.00
0.037   #63  $2.50
0.038   #62  $1.50
0.039   #61  $1.50
0.0394 1.00  $1.00

 


Deluxe 40-piece Micro Drill Set

Jet Drills 80-72 and 71-60

Myron’s Mopeds two case deluxe micro drill set, 80 to 72 (small) and 71 to 60 (large) plus many in-between sizes.
Price $45

Slide clear top plastic until hole is over drill (and pointer is on desired drill number). Only lets one drill out at a time. Never take out more than one at a time, or they can get mixed. The case keeps them organized. If any get lost, dull, or broken, individual drills can be bought at some hardware stores for $3-$4 each.

Useful for sizing to tell how big a jet really is (sometimes they’re drilled out or labeled wrong).

Useful for cleaning varnish or corrosion coating the inside of an old jet. It doesn’t really clean out any other way. The drill is used as a file, held with a needlenose pliers.

Useful for drilling jets to make a new size, as an alternative to buying ones. The drill is held with a needlenose pliers, and the jet is rotated with your fingers, with a drop of oil. To go down in size, fill the hole with solder and re-drill it smaller.

 

 

 

Here is a pin vise, a mini drill chuck, price $8

 

 

 

 

 

 

 


Other Tools for Cleaning Jets

Using a micrometer to measure a 0.017 wire

Using a micrometer to measure a 0.017″ wire

Guitar steel string 17 thousandths of an inch

Guitar string

Guitar Steel Strings in the smaller sizes are excellent tools for cleaning small holes. Here is a 0.0170 inch steel wire guitar string, perfect for cleaning out a 1974-85 Tomos stock jet size 46 that has a 0.0175 inch hole. A Honda Express NC50 (Keihin) carburetor, has a long brass idle jet tube with a tiny jet hole at the far end, too far for a drill to reach. For that, only a 2 or 3 inch piece of 0.010″ steel guitar string will reach to clean it. Ultrasonic cleaners, carb spray, or soaking are not effective for that. Other examples are a Sachs 52 jet 0.0190 would be cleaned by a 0.018″ wire, or a Motobecane 230 jet 0.023″ would be cleaned by a 0.022″ wire. The wire has to be a little smaller than the hole. Plain steel strings range from 0.008″  to 0.017″ in steps of 0.001″. Wound strings range from 0.017″ to 0.065″. 

 

Torch Tip Cleaner Set

Torch Tip Cleaner Set

Root Canal Files

Root Canal Files (say ahhh)

Welding Torch Tip Cleaners are another excellent tool for cleaning small holes. The tip has a cutting surface but not the sides. So it is made to clean the hole without widening it.

Wire Feeler Gauge Sets: There are also wire gauge measuring sets that look the same as the torch cleaner set shown.

Dentist’s Root Canal Files are also good for cleaning small holes. Color coded files range from 0.06 to 1.10 mm (0.0024 to 0.0433 inch).