Myrons Mopeds

Contents
  carburetor  years  mph  Honda model
14. PA29C-B  ’84-85 30 NQ50 Spree
14. PA29D-A  ’84-85 25 NQ50 Spree
14. PA29C-D  ’85-85 30 NQ50 Spree
14. PA29D-B  ’85-85 25 NQ50 Spree
14. PA29H-A  ’86-86 30 NQ50 Spree
14. PA29???   ’86-86 25 NQ50 Spree
14. PA29???   ’87-87 30 NQ50 Spree
14. PA29???   ’87-87 25 NQ50 Spree
15. PA05A-H  ’83-84 30 NB50M Aero
16. PA04G-A  ’85-85 30 NB50M Aero (US)
15. PA04P-A  ’86-86 30 NB50 Aero (US)
15. PA04W-A ’87-87 30 NB50 Aero (US)
17. PB15A-A  ’80-83 00 C70 Passport

14. Keihin

# size  carb   jet code mph   model code GK8
a 12 PA29C-B 68  671  30  ’84-85 NQ50 Spree
b 11 PA29D-A 62  731  25  ’84-86 NQ50 Spree
c 12 PA29C-D 68  673  30  85-‘85 NQ50 Spree
d 11 PA29D-B 62  733  25  85-‘85 NQ50 Spree
e 12 PA29H-A 68  871  30  86-‘86 NQ50 Spree
f  11 PA29???  62  881  25  86-‘86 NQ50 Spree
g  12 PA29???  68  601  30  87-‘87 NQ50 Spree
h 11 PA29???  60  611  25  87-‘87 NQ50 Spree

1. 1983 Honda NB50M Aero
2. 1985 Honda NQ50 Spree
3. 16100-GK8-673 Keihin PA 29C-D

Flange Mount: The flange mount holes on ’84-87 Spree carburetors are spaced 35mm, center-to-center. That is different from ’74-78 PC50 32mm, ’82-83 NC50-AA 36mm, ’77-83 NC50 38mm, ’79-on Z50 32mm, and ’76-78 Z50 38mm.

These were zippy 50cc two-stroke automatic scooters that maxed out at 30mph to meet many US state’s moped laws. They have electric start so there is 12 volt battery power to operate an automatic electric choke. They also have a gas gauge and an automatic vacuum petcock on the gas tank. You don’t have know very much to operate one. They had a CVT variator that continuously changes the belt drive pulley size ratio, for very quick acceleration. 

Idle Mixture Screw: The idle mixture screw is an “air screw” that blocks off an air channel.

Main Jet: The main jet is a screw-in, recessed-type, M6-0.75 thread, size 68 (0.68mm).

Pilot Jet: The idle jet is not replaceable. It is inside the upper end of the brass tube, pressed into the main body, on the engine side of the main jet.

Float Seat: This carb does not have a replaceable float needle valve seat. The seat is part of the main body, and must be cleaned and polished with a spinning Q-tip.

Float: non-stirrup type white plastic 16013-147-004 see 6-4.0b, non-stirrup needle valve 16155-883-005 see 6-2.0b

Top Cap: M18 x 1 thread

Byster set: This is the automatic choke unit aka by-starter for cold starting. It enriches the fuel-air mixture when the engine is cold. 

The float bowl gasket in the illustration looks like the NC50-type, but it’s not. The actual gasket has an additional loop, for a vent and overflow. 

1. 16010-GK8-601, 2. 16010-GE8-305, 3. 16010-GS6-305 gasket sets

Speed versions parts: Besides the 11 and 12 mm carb body difference, the only parts difference between 25 and 30 mph is the main jet and the needle jet. This is evident by scanning down the 8 quantity columns abcdefgh.

Speed versions codes: For the first carburetor in a series of superseded carbs, the last 3 digits of the carburetor part number indicate the speed version. They are colorized below, blue or aqua, to show the pattern. The needle jet part numbers also have those speed version codes.

c# 84858687
o# abcde f gh price  Honda part#    carburetor   NQ50 version
10 10100000 N/A  16100-GK8-671
10 10100000 N/A  16100-GK8-672 PA29C-B ’84-85 US 30
10 01010000 N/A  16100-GK8-731
10 01010100 N/A  16100-GK8-732 PA29D-A ’84-86 US 25
10 00100000 N/A  16100-GK8-673 PA29C-D ’85 US 30
10 00010000 N/A  16010-GK8-733 PA29D-B ’85 US 25
10 00001000 N/A  16100-GK8-871
10 00001000 N/A  16100-GK8-872
10 00001000 N/A  16100-GK8-873
10 00001000 N/A  16100-GK8-874
10 00001000 N/A  16100-GK8-875
10 00001000 N/A  16100-GK8-893 PA29H-A ’86 US 30
10 00000100 N/A  16100-GK8-881
10 00000100 N/A  16100-GK8-882
10 00000100 N/A  16100-GK8-883 PA000-0 ’86 US 25
10 00000010 N/A  16100-GK8-601
10 00000001 N/A  16100-GK8-602 PA000-0 ’87 US 30
10 00000010 N/A  16100-GK8-611
10 00000010 N/A  16100-GK8-612 PA000-0 ’87 US 25
c# abcde f gh  price  Honda part#    parts list
o1 11111100 $00 16010-GK8-003 
o1 11111100 $21 16010-GE8-305 gasket solo-set   b c g v o x
o1 00001111 $24 16010-GK8-601 gasket solo-set   b c g v z 
o1 11111111 $26 16010-GE8-315 gasket multi-set b c g v z x
o1 11111111 $28 16010-GS6-305 gasket multi-set b c g v z x d
1b 11111111 $$8 16110-GN2-871 top rubber washer 13 x 16.5 x 1
1c 11111111 $$2 00000-000-000 intake o-ring 2 x 20 (24 od)
1g 11111111 $$2 00000-000-000 drain plug o-ring 1.5 x 4 (7 od)
1v 11111111 $20 00000-000-000 float gasket  2.5 x 1.5 with loop
1z 11111100 0$2 00000-000-000 byster o-ring 1 x 16 (18 od)
1x 00001111 N/A  00000-000-000 byster o-ring 1 x 12 (14 od)
o2 00000101 N/A  16012-GK8-631
o2 00000101 N/A  16012-GK8-601 need. set 30 for 25
o2 10101010 N/A  16012-GK8-671 needle set 30 mph
o2 01010000 N/A  16012-GK8-731 needle set 25 mph
o3 11111111 $28 16013-147 -004 float set  3a 3b 3c
3a 11111111 $21 00000-000-000 float bare hollow white plastic regular
3b 11111111 $$4 00000-000-000 hinge pin substitute Ø2 x 18.5
3c 11111111 $$3 0-93600-04006 hinge screw M4x6 sunk phillips
o4 11111111 $30 16014-GK8-003 top set
o5 11000000 N/A  16015-GK8-003
o5 11000000 N/A  16015-GG2-711 chamber set
o5 00111000 $37 16015-GK8-671 chamber set
o5 00000111 N/A  16015-GK8-781 chamber set
o6 11111111 N/A  16016-197 -004 screw set (idle air)
o6 00001100 N/A  16016-GK8-871 screw set (idle air)
o7 11111111 N/A  16022-GC7-004
o7 11111111 N/A  16022-GC7-611 throttle valve set
o8 11111111 N/A  16028-187-003
o8 11111111 N/A  16028-GC8-004 screw set B (idle speed)
8a 11111111 $$4 00000-000-000 idle speed screw M4x19 special
8b 11111111 $$2 00000-000-000 idle speed screw spring Ø5.6 x 10
o9 11000000 N/A  16046-GK8-003 byster set ∅16 ’84
o9 00111100 N/A  16046-GK8-671 byster set ∅16 ’85 CB DA O0 O0 ’86 DA
o9 00111100 N/A  16046-GK8-672 byster set ∅16 ’85 CB DA DB CD ’86 DA
o9 00111100 N/A  16046-GK8-673 byster set ∅16 ’85 CB DA DB CD ’86 DA
o9 00001111 N/A  16046-GK8-781 byster set ∅12 ’86-87
o9 00001111 N/A  16046-GK8-631 byster set ∅12 ’86-87
o9 00001111 N/A  16046-GK8-632 byster set ∅12 ’86-87
11 11111111 $$8 16110-GN2-871 top rubber washer 13 x 16.5 x 1
12 11111111 0$2 16118-166-004 rubber boot substitute Dellorto
13 11111111 $22 16155-883-005 float needle valve
14 11111111 N/A  16186-GJ2-004 byster set plate
15 11110000 N/A  16190-GJ2-004
15 11110000 N/A  16190-GR1-003 byster cover
15 00001111 N/A  16190-GK8-003 byster cover
16 00001111 N/A  16190-GK8-870 outer cover
17 22222222 0$1 93892-0400808 byster screw M4 x 8 philips
18 22222222 0$1 93892-0401208 bowl screw M4 x 12 philips
19 11111111 N/A  95003-0500860M drain hose
20 10101010 N/A  99101-187 -0680
20 10101010 0$7 99112-GHB-0680 jet 68  30mph ’84-87
20 01010100 N/A  99101-187 -0620
20 01010100 N/A  99101-ZG0-0620 jet 62  25mph ’84-86
20 00000001 N/A  99101-393 -0600 jet 60  25mph ’87

15. Keihin

#      carb    0 model code GE8
a PA05A-H ’83-84 NB50M Aero (US)
b PA05???  84-’84 NB50M Aero (DK)
c PA05???  84-’84 NB50M Aero (UK)
d PA05???  84-’84 NB50M Aero (DE)
e PA05???  84-’84 NB50M Aero (FR)
f  PA05???  84-’84 NB50M Aero (CA)

 
a. 16100-GE8-673 Keihin PA 05A-H for USA
b. 16100-GE8-013 Keihin PA 05??? for Denmark

o# abcde f  price  Honda part#    carburetor
10 100000 N/A 16100-GE8-672
10 100000 N/A 16100-GE8-673
10 100000 N/A 16100-GE8-613 PA05A-H ’83-84 NB50M (US)
10 010000 N/A 16100-GE8-003
10 010000 N/A 16100-GE8-013 PA05???       ’84 NB50M (DK)
10 001000 N/A 16100-GE8-601
10 001000 N/A 16100-GE8-602
10 001000 N/A 16100-GE8-603
10 001000 N/A 16100-GE8-613 PA05???       ’84 NB50M (UK)
10 000100 N/A 16100-GE8-611
10 000100 N/A 16100-GE8-612
10 000100 N/A 16100-GE8-613 PA05???       ’84 NB50M (DE)
10 000010 N/A 16100-GE8-621
10 000010 N/A 16100-GE8-622
10 000010 N/A 16100-GE8-623
10 000010 N/A 16100-GE8-613 PA05???       ’84 NB50M (FR)
10 000001 N/A 16100-GE8-671
10 000001 N/A 16100-GE8-672
10 000001 N/A 16100-GE8-673
10 000001 N/A 16100-GE8-613 PA05???       ’84 NB50M (CA)
o# abcde f  price  Honda part#    parts list
o1 111111 N/A 16010-GE8-004 
o1 111111 N/A 16010-GE8-003 gasket solo-set   oo oo 1g 1v 1z
o1 111111 $21 16010-GE8-305 gasket solo-set   1b 1c 1g 1v 1z
o1 111111 $22 16010-GE8-315 gasket multi-set 1b 1c 1g 1v 1z 1x
1b 111111 $$8 00000-000-000 top seal washer 13 x 16.5 x 1
1c 111111 $$2 00000-000-000 intake o-ring 2 x 20 (24 od)
1g 111111 $$2 00000-000-000 drain o-ring 1.5 x 4 (7 od)
1v 111111 $20 00000-000-000 float gasket  2.5 x 1.5 with loop
1z 111111 0$2 00000-000-000 byster o-ring 1 x 16 (18 od)
1x 000000 N/A  00000-000-000 choke o-ring 1 x 12 (14 od)
o2 100000 $00 16012-GE8-671 needle set 2a 2b 2c 2d
2a 111111 0$5 16156-044-004 jet needle w-clip
2b 111111 0$2 16157-044-004 jet needle e-clip 1.5 for Ø2.0 needle
2c 100000 $00 00000-000-000 jet needle
2d 100000 $00 00000-000-000 needle jet
o3 111111 $28 16013-147-004 float set 3a 3b 3c white regular
3a 111111 $21 00000-000-000 float bare hollow white plastic regular
3b 111111 $$4 00000-000-000 hinge pin substitute Ø2 x 18.5
3c 111111 $$3 0-93600-04006 hinge screw M4x6 sunk phillips
o4 111111  16014-147-004 top set substitute M18-1.0 4a 1b
o5 111111 N/A 16015-GE8-003 chamber set 5a 5b 1v 1g
5a 111111 N/A 00000-000-000 float bowl
5b 111111 N/A 00000-000-000 drain screw
o6 111111 N/A 16016-197-004 screw set idle air
o7 111111 N/A 16022-GE8-003
o7 111111 N/A 16022-GC7-004 valve set
o8 111111 N/A 16028-187-003
o8 111111 N/A 16028-GC8-004 screw set idle speed
o9 111111 N/A 16046-GE8-023
o9 111111 N/A 16046-GE7-023
o9 111111 N/A 16046-GE7-033 bystarter (choke) set
o9 011111 N/A 16046-GE8-621
o9 011111 N/A 16046-GE8-622 bystarter (choke) set
11 011111 N/A 16118-190-004
11 111111 N/A 16118-086-004
11 111111 0$2 16118-166-004 rubber boot substitute Dellorto
12 111111 $22 16155-883-005 float needle valve
14 111111 N/A 16198-GA7-701 air vent tube
16 222222 0$1 93892-0401208 bowl screw M4 x 12 philips
18 111111 N/A 95002-02650 air vent tube clip
19 011111 0$7 99101-187-0750 main jet 75
19 100000 0$7 99101-187-0780 main jet 78
19 011111 0$7 99101-187-0800 main jet 80

16. Keihin

# size  carb 0 model code GN2
a 14 PA04G-A  ’85 NB50M Aero (US)
b 14 PA04P-A  ’86 NB50 Aero (US)
c 14 PA04W-A ’87 NB50 Aero (US)
d 14 PA04H-A  ’85 NB50M Aero (UK)
e 14 PA04???   ’85 NB50M Aero (FR)
f  14 PA04???   ’85 NB50M Aero (CA)

 
a. 16100-GN2-633 Keihin PA 04G-A

o# abcde f price  Honda part#    carburetor 
11 100000 N/A 16100-GN2-633 PA04G-A  ’85 NB50M (US)
11 100000 N/A 16100-GN2-672 PA04???   ’85 NB50M (US)
11 010000 N/A 16100-GN2-871
11 010000 N/A 16100-GN2-872 PA04P-A  ’86 NB50 (US)
11 001000 N/A 16100-GN2-762 PA04W-A ’87 NB50 (US)
11 000100 N/A 16100-GN2-601
11 000100 N/A 16100-GN2-602 PA04H-A      ’85 NB50M (UK)
11 000010 N/A 16100-GN2-621
11 000010 N/A 16100-GN2-622 PA04???       ’85 NB50M (FR)
11 000001 N/A 16100-GN2-671 PA04???       ’85 NB50M (CA)
o# abcde f price  Honda part#    parts list
o1 111111 N/A 16010-GJ2-004 gasket solo-set
o1 111111 N/A 16010-GY3-505 gasket multi-set
o1 111111 N/A 16010-GY3-515 gasket multi-set
o2 100000 N/A 16012-GN2-671 needle set 2a 2b 2c 2d
2a 111111 0$5 16156-044-004 jet needle w-clip
2b 111111 0$2 16157-044-004 jet needle e-clip 1.5 for Ø2.0 needle
2c 100000 N/A 00000-000-000 jet needle
2d 100000 N/A 00000-000-000 needle jet
o3 111111 $28 16013-147-004 float set 3a 3b 3c white regular
3a 111111 $21 00000-000-000 float bare hollow 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
o4 111111  16014-147-004 top set substitute M18-1.0 4a 1b
26 100000 0$7 99101-187-0750 main jet 75
26 100111 0$7 99101-187-0800 main jet 80
26 011000 N/A 99101-187-0820 main jet 82

17. Keihin

#    carb 0 model code GB4
a  PB15A-A  ’80-83 C70 Passport (US)

1. Keihin PB15A-A, 2. gasket set 16010-957-305

Flange Mount: 36? mm hole spacing

.# a price  Honda part#    carburetor 
o8 1  N/A 16100-174-673  PB 000-A ’80-80 C70  Passport (US)
o8 1  N/A 16100-174-772  PB 000-A ’81-81 C70  Passport (US)
o8 1  N/A 16100-GB5-671 PB 15A-A ’82-83 C70 Passport (US)
.# a price  Honda part#    parts list
o1 1  N/A 16010-GB4-013 gasket solo-set
o1 1  N/A 16010-141-305 gasket multi-set
o1 1  N/A 16010-957-305 gasket multi-set

Contents
carburetor    years  Honda model
09. Z50A 0-0 ’68-69 Z50A K0
09. Z502 0-0 ’69-71 Z50A K1-K2
10. 655-A 00 ’72-75 Z50A K3-K6
10. 674-A 00 ’70-75 QA50 K0-K3
11. PA03A-A  ’76-78 Z50A K7-K9
11. PA03C-A  ’79-81 Z50R
11. PA03D-A  ’82-85 Z50R
11. PA03F-B   ’86-87 Z50R
12. PA03H-A  ’88-88 Z50R
12. PA03H-B  ’88-91 Z50R
12. PA03M-A  ’92-93 Z50R
12. PA03N-A  ’94-99 Z50R
13. PA42A-C  ’00-03 XR50R
13. PA????     ’04-09 CRF50F

9. Keihin

#   carb  code    frame# range  00  US models
a  Z50A  045  up to Z50A-255950 ’68-69 Z50A K0
b  Z502  045  after Z50A-255950 ’69-70 Z50A K1
b  Z502  045  after Z50A-255950 ’70-71 Z50A K2

1. Keihin Z50A, Z502 on 1968-71 Z50A
2. 1968-71 Z50A carb kit

Flange Mount: 32mm hole spacing, 2 x 18 (22 od) o-ring

Main Jet: This carb has a screw-in main jet size 50.

Pilot Jet: It also has a screw-in idle (pilot) jet size 38.

Float Seat: It also has a screw-in float needle seat, replaceable.

Float: no-stirrup metal-tip needle valve, metal swinging float

The Z50A and Z502 carbs are the same except for the needle jet #12 and rubber cable pipe #10.

o# ab price  Honda part#    carburetor
o9 10  N/A 16100-045-670 Z50A  ’68-69 Z50A up to 255950
o9 01  N/A 16100-045-671 Z502  ’69-71 Z50A after 255950
o# ab price  Honda part#   gaskets
o1 11  N/A 16010-045-670 gasket set
oo 11  N/A 00000-000-000 bowl gasket
oo 11  N/A 00000-000-000 top rubber washer 12 – 18 x 1.0
oo 11  N/A 00000-000-000 intake o-ring 2.0 x 16 (20 od)
oo 11 0$2 00000-000-000 1q float fiber washer 3 – 6 x 0.5
oo 11 0$5 16174-045-004 1r drain o-ring 2.0 x 4 (8 od)
o# ab price  Honda part#   parts list
o2 11  N/A 16011-045-004 valve set
o3 11  N/A 16012-045-670 needle set
o4 11  N/A 16013-045-004 float set
o5 11  N/A 16014-045-004 top set
o6 11  N/A 16015-045-670 chamber set
o7 11  N/A 16016-045-014 screw set A
o8 11  N/A 16022-045-600 slide set
10 10  N/A 16118-045-770 rubber cap to-255950
10 01  N/A 16194-045-770 rubber cap red stripe
11 11  N/A 16123-049-004 choke cover
12 11  N/A 16139-045-004 needle jet holder to-108295
12 11  N/A 16139-045-014 needle jet holder 108296-on
13 11  N/A 16142-049-004 choke valve
26 11  N/A 0-99124-05004 
26 11  N/A 0-99101-05004 main jet #50 to-108295
26 11  N/A 99114-076-0500 main jet 50 108296-on
27 11  N/A 0-99153-03804
27 11  N/A 0-99151-03804 slow jet #38

10. Keihin

#   carb  code    US models
a  655-A  130  ’72-75 Z50A K3-K6
b  674-A  114  ’70-72 QA50 K0
b  674-A  129  ’73-75 QA50 K1-K3

1. Keihin 655-A on 1972-75 Z50A
2. 1974-75 Z50A carb kit, missing the drain plug o-ring and jet pad disk.
3. 1970-73 Z50A carb kit also had a float seat and a float seat washer.
3. 16010-114-004 gasket set 
4. 16015-114-004 drain screw for 1970-73 Z50A

Flange Mount: 32mm hole spacing, no o-ring groove on carburetor. Instead the o-ring groove is on the intake manifold. Since the 2 x 18 (22 od) intake o-ring is not part of the carburetor, it is not in the Honda gasket set 16010-114-004, or the multi-app set 16010-114-305.

Main Jet: This carb has a “long” press-in jet, with a rubber pad disk under it.

Pilot Jet: The idle jet is not replaceable. It is inside the upper end of the brass tube, pressed into the main body, on the engine side of the main jet.

Float Seat early: The 1970-73 carburetor had a screw-in float needle seat, that was replaceable, like in the illustration.

Float Seat late: The 1974-75 carburetor did not have a replaceable float needle valve seat. The seat was part of the main body, and must be cleaned and polished with a spinning Q-tip.

Float: no-stirrup metal-tip needle valve, swinging float 16013-114-004

Top Cap: M18 x 1.0 thread

Drain screw: 1970-73 chamber set 16015-114-004 had a M4-0.7 thread drain screw with a 2 x 4 (8 od) o-ring. 1974-75 had a M6-0.75 thread drain screw with no o-ring. 1976-78 had a M6-1.0 thread drain screw with a 2 x 2.5 (6.5od) o-ring. 1979-later had a 1.5 x 4 (7od) drain screw o-ring.

o# abcd price  Honda part#    carburetor
o9 1000  N/A 16100-120-010 655-A      ’72-73 Z50A
o9 0100  N/A 16100-120-010 655-A      ’74-75 Z50A
o9 0010  N/A 16100-114-014 674-A K   ’70-71 QA50 K0 to 1057061
o9 0001  N/A 16100-114-024 674-A-K1 ’71-72 QA50 K0 1057062-on
o9 0001  N/A 16100-129-000 674-A K1 ’73-75 QA50 K1 K2 K3
o# abcd price  Honda part#    parts list
o1 1111  $24 16010-114-004 gasket solo set   d e h n p r
o1 0000  N/A 16010-114-305 gasket multi set d e h n p r q
1e 1111 $14 16197-063-004 e jet support disk Ø7.3 x 1.75
1h 1111 $$2 00000-000-000 h intake o-ring 2 x 18 (22 od)
1d 1111 0$2 16176-551-004 d main jet o-ring 1 x 3 (5 od)
1r 1111 0$5 16174-045-004 r drain screw o-ring 2 x 4 (8od)
1p 1111 0$5 16171-044-004 p top rubber washer 10 x 15 x 1
1n 1111 0$3 16173-063-004 n float o-ring 1.5 x 40 (43 od)
02 1111  N/A 16011-045-004 float valve set
03 1100  N/A 16012-120-004 jet needle set
03 0011  N/A 16012-114-004 jet needle set
04 1111  N/A 16013-114-004 float set
05 1111  N/A 16014-120-004 top set
06 1111  N/A 16015-114-004 float chamber set
07 1111  N/A 16016-045-610
07 1111  N/A 16016-063-004 adjustment screw set
7a 1111  N/A 16162-044-004 idle air screw
7b 1111  N/A 16181-001-004
7b 1111  N/A 16181-250-004 idle air spring
7c 1111  N/A 16163-063-004 idle speed screw
7d 1111  N/A 16185-044-004 idle speed spring
08 1100  N/A 16022-120-004
08 1100  N/A 16022-120-305 throttle valve-spring set
8a 1100  N/A 16111-120-004
8a 1100  N/A 16111-120-305 throttle valve
8b 1100  N/A 00000-000-000 throttle spring
08 0010  N/A 16022-063-004 throttle valve-spring set
08 0001  N/A 16022-129-004 throttle valve-spring set
10 0010  N/A 16194-045-004
10 1111  N/A 16194-045-770 rubber cap
11 1111  N/A 93500-030-050 cross screw 3 x 5 choke
12 2222  $$1 93500-040-120 pan screw 4 x 12 float
13 1111  .50  0-94111-03000 spring washer 3 choke lever
14 2222  .50  0-94111-04000 spring washer 4 float bowl
o# abcd price  Honda part#    long push-in jets
15 1000  N/A 99201-114-520 jet 52 ’72-73 Z50A K3 to K4
15 0100  N/A 99201-114-550 jet 55 ’74-75 Z50A K5 to K6
15 0010  N/A 99201-114-480 jet 48 ’70-73 QA50 K0 to 1057061
15 0001  N/A 99201-114-520 jet 52 ’70-75 QA50 K0 105762-on to K3

11. Keihin

#   carb 00 size code  US models
a  PA03A-A  10  130  ’76-78 Z50A K7-K9
b  PA03B-A  11  130  79-’79 Z50A K9 up to 5022291
c  PA03C-A  11  181  ’80-81 Z50R A,B after 5022291
d  PA03D-A  11  181  ’82-85 Z50R C,D,E,F
e  PA03F-B  11  181  ’86-87 Z50R G,H

In 1979 the model name changed from Z50A to Z50R, and the name Mini Trail was dropped.

1. 16100-130-642 Keihin PA 03A-A for 1976-78 Z50A from cmsnl.com
2. 16100-165-004 Keihin PA 03B-A for 1979 Z50R
3. 16100-165-014 Keihin PA 03C-A for 1979-81 Z50R from cmsnl.com
4. 16100-181-751 Keihin PA 03D-A for 1982-85 Z50R

1. 16010-181-832 Keihin PA 03F-B for ’86-87 Z50R from cmsnl.com
2. 1976-78 Z50A carb kit D348 thick needle, #58 push-in jet. The drain screw and jet support pad are missing.
3. 1979-81 Z50R carb kit D117 thin needle, #58 screw-in jet. Left to right: drain screw, needle jet (emulsion tube), idle air screw, idle speed screw, float needle

Flange Mount: 38 mm hole spacing 1976-78.  32 mm hole spacing 1979-87.

Pilot Jet: The idle jet is not replaceable. It is inside the upper end of the brass tube, pressed into the main body, on the engine side of the main jet.

Main Jet:  For some reason in 1979 Honda wanted to make their jets tamper-proof. It’s funny that they went from one extreme to the other, from jets that fall out too easy, to jets that never come out. Both the NC50 and the Z50 changed to “fixed” jets (not replaceable) in late 1978 and 1979. After 1981 the jet was a screw-in, thankfully, like in the illustration

Float Seat: This carb does not have a replaceable float needle valve seat. The seat is part of the main body, and must be cleaned and polished with a spinning Q-tip.

Carb Kit: Beware of low-cost carburetor kits. In the kit at the right several things are wrong or made badly. 1) it is missing the press-in jet pad disk, 2) the jet o-ring was too big to allow the jet to press in. You can see it seems big in the photo. It was size 1.5 x 4 instead of 1 x 3, 3) the float needle was longer than stock, and the wire stirrup was bent badly in two ways. The throttle (jet) needle was D117 thin instead of D348 thick.

Float: In 1979 the float and float needle changed, from stirrup-type needle valve with black foam float, to no-stirrup needle valve 16155-883-005 with white plastic float 16013-147-004. Like before, the float needle has a rubber cone upper tip and a spring-loaded lower tip. 

Float Bowl: The 1979-later float bowl no longer has a press-in jet support pad disk 7.5 x 1.8mm.

16010 gasket sets: 1. 081-004, 2. 081-014, 3. 165-621, 4. 181-305

 
#  size top pipe  price  Honda part#   carburetors
a 10 38 20 long   N/A 16100-130-641 
a 10 38 20 long   N/A 16100-130-642 PA03A-A ’76-78 Z50A 
b 11 32 20 long   N/A 16100-165-004 PA03B-A ’79 Z50R 
c 11 32 20 long   N/A 16100-165-014 PA03C-A ’79- Z50R, Z50G,J,GZ,JZ
c 11 32 20 long   N/A 16100-165-305 PA03C-B ’80-81 Z50R, Z50G,J,GZ,JZ
d 11 32 20 long   N/A 16100-181-751 PA03D-A ’82-85 Z50R 
e 11 32 20 none  N/A 16100-181-830, 16100-181-831
e 11 32 20 none  N/A 16100-181-832 PA03F-B ’86-87 Z50R 
e 11 32 20 none $75 16100-181-832P “W” replacement carb
f  10 32 20 long   N/A 16100-165-731 PA030-0  ’79- Z50J,G DE, ’82-84 Z50J FI, Z50GZ DE
g 10 32 20 short  N/A 16100-165-732
g 10 32 20 short  N/A 16100-165-733 PA030-0 ’85- Z50J DE
h 11 32 20 short  N/A 16100-165-306 PA030-0 ’86-96+ Z50J FI
i  11 32 18 short  N/A 16100-165-A11 .
i  11 32 18 short  N/A 16100-165-A12 PA000-0 Z50J1 JP, round float bowl

o# abc de  f gh i price  Honda part#    gasket sets
o1 10000 0000 $35 16010-081-004 solo-set  1a o d s f o h i
o1 01100 1100 $25 16010-081-014 solo-set  1a o o o f g h
o1 00011 0000 $30 16010-181-831 solo-set  oo o o o f g h o l
o1 01111 1100 $32 16010-181-305 multi-set 1a o o o f g h o l
o1 00000 0010 $30 16010-165-981 solo-set   1a o d o f g h
o1 11100 1010 $37 16010-143-305 multi-set 1a c d s f g h i
o1 00000 0001  N/A 16010-165-A11 solo-set   1b c o o . g o . . m
o# abc de  f gh i price  Honda part#    gaskets
1a 10000 1110 $$3 00000-000-000 top rubber washer 10 x 18.5 x 1
1b 00000 0001 $$8 00000-000-000 top rubber washer 13 x 16.5 x 1
1c 00000 0001 $$2 00000-000-000 intake o-ring 2 x 20 (24 od) 
1d 10000 0010 0$2 16176-551-004 jet o-ring 1 x 3 (5 od)
1f  11111 1110 $21 00000-000-000 float gasket  Ø1.5 NC50-type
1g 01111 1111 $$2 00000-000-000 drain o-ring 1.5 x 4 (7 od)
1h 11011 1110 $$2 00000-000-000 intake o-ring 2 x 18 (22 od)
1i  10000 0000 0$2 16175-260-004 drain o-ring 2 x 2.5 (6.5 od)
1l  01111 0000 0$4 16110-181-831 top rubber washer 13 x 18.5 x 1
1m00000 0001 N/A 00000-000-000 float bowl o-ring 2.0 x 49
1s 10000 0000 $14 00000-000-000 jet pad disk Ø7.5 x 1.8 
o# abcde  f gh i price  Honda part#    parts list
02 10000 0000  N/A 16012-130-640 needle set 03AA
o2 01000 0000  N/A 16012-165-014 needle set 03BA 
o2 00111 0000  N/A 16012-181-831 needle set 03CA, 03DA, 03FB
o2 00000 1100  N/A 16012-165-731 needle set
o3 10000 0000  N/A 16013-099-691
o3 10000 0000 $46 16013-143-620 float set 3a oo 3c 3d black stirrup
o3 01111 1100 $28 16013-147-004 float set oo 3b 3c 3d white regular
3a 10000 0000  N/A 00000-000-000 float bare, solid black foam stirrup
3b 01111 1110 $21 00000-000-000 float bare hollow white plastic regular
3c 11111 1110 $$4 00000-000-000 hinge pin substitute Ø2 x 18.5
3d 11111 1110 $$3 0-93600-04006 hinge screw M4x6 sunk phillips
o4 11100 0100  N/A 16014-130-640 top set with pipe 4a 1a M20-1.0
o4 00011 0000  N/A 16014-GB1-911
o4 00011 0000  N/A 16014-GB1-912 top set with pipe 4a 1l M20-1.0
o4 00000 1100  N/A 16014-165-622 top set
o4 00000 0001  N/A 16014-000-000 top set with pipe 4a 1b M18-1.0
o5 10000 0000  N/A 16015-130-640 chamber set 5a 1e 1f 5b 1g
o5 01000 0000  N/A 16015-099-691 chamber set 5a oo 1f 5b 1g
o5 00111 0000  N/A 16015-130-641 
05 00111 1100  N/A 16015-165-621 chamber set 5a oo 1f 5b 1g
o6 11000 0000  N/A 16016-143-620 screw set
o6 00111 1100  N/A 16016-165-004 screw set A & B
6a 00111 0000  N/A 16016-165-621 
6a 00111 0000  N/A 16016-165-505 screw set A (idle air)
6b 00001 0000  N/A 16208-GC8-004 screw set B (idle speed)
o7 11000 0000  N/A 16022-081-004
o7 11000 0000  N/A 16022-HB2-003 slide set
o7 00111 0000  N/A 16022-165-004
o7 00111 0000  N/A 16022-GW8-671
o7 00111 0000  N/A 16022-GW8-672 slide set
o7 00000 1100  N/A 16022-165-731 slide set small
7a 00111 0000  N/A 16022-GW8-672 slide only ∅12.9
7b 00111 0000  N/A 16022-GW8-672 spring only ∅8.9  x 45
o9 11110 1000  N/A 16118-121-014 rubber cable pipe cover long
o9 00000 0110  N/A 16118-GB4-003 rubber cable pipe cover short
10 10000 0000  N/A 16011-143-620
10 10000 0000  N/A 16011-881-741 float needle valve  stirrup
10 01111 1110 $22 16155-883-005 float needle valve regular
11 22222 2220 0$1 93892-04012-08 screw & washer M4x12 pan phillips
o# abc de f gh i price  Honda part#    jets
14 10000 0000 $16 99201-081-0580 main jet push-in #58 0.0228″
14 01100 0000  N/A fixed needle jet and main jet pressed in 0.0228″
14 00011 0010 0$7 99101-187-0580 main jet screw-in #58 0.0228″
18 11111 1110  N/A (not sold separately) idle jet press-in tube 0.015″ pinhole

12. Keihin

#   carb 000  code    Honda US model
a  PA 03H-A  GW8 88–’88 Z50R up to JS900485
b  PA 03H-B  GW8 ’88-91 Z50R after JS900485
c  PA 03M-A  GW8 ’92-93 Z50R
d  PA 03N-A  GW8 ’94-99 Z50R
e  PA 42A-C  GW8 ’00-03 XR50R 
a  PA 42A-C  GEL  ’04-05 CRF50F
f   PA 42???   GEL  ’06-06 CRF50F 

 
1. 16100-GW8-682 Keihin PA 03M-A
2. 16100-GW8-305 Keihin PA 03N-A  from cmsnl.com
3. 16100-GEL-702 Keihin PA 42A-C
4. CRF50F carb. The gasket for this was in use for over 34 years!

In 2000 the Z50R was replaced by the XR50R. The PA03N-A carburetor became PA42A-C, but only the needle jet and the idle air screw changed.

In 2004 the XR50R was replaced by the CRF50F. The PA42A-C carburetor did not change until 2006.

2006 was the last year of CRF50F in the US, but in Europe it continued up to 2011.

Flange Mount: 32mm hole spacing

Main Jet: screw-in #58, M6-0.75

Float: no-stirrup type white plastic 16013-147-004, needle valve 16155-883-005

Top Cap: M20-1.0 thread

Idle Mixture Screw: For the entire Z50A, Z50R, XR50R, CRF50F year range 1968 to 2006, the idle mixture screw was an air type, not a fuel type. An idle air screw blocks an air tunnel, so tighter is less air (richer). An idle fuel screw blocks off a fuel tunnel, so tighter is less fuel (leaner). 

1. 1992-98 Z59R carb kit, 2. 16010-181-831 for PA 03H 03M 03N
3. 16010-181-305 gasket set for PA 03H 03M 03N
4. 16016-GW8-672 This idle air screw looks like an idle fuel screw.

o# abcde f price  Honda part#     carburetor
o8 100000  N/A 16100-GW8-671
o8 100000  N/A 16100-GW8-672 PA 03H-A 1988 Z50R up to JS900485
o8 010000  N/A 16100-GW8-673 PA 03H-B ’88-91 Z50R mix screw changed
o8 001000  N/A 16100-GW8-680
o8 001000  N/A 16100-GW8-681
o8 001000  N/A 16100-GW8-682 PA 03M-A ’92-93 Z50R
o8 001000  N/A 16100-GW8-780
o8 001000  N/A 16100-GW8-791
o8 000100  N/A 16100-GW8-792 PA 03N-A ’94-99 Z50R
o8 111100  N/A 16100-GW8-305 PA 03N-A replacement
o8 000010  N/A 16100-GEL-701 
o8 000010  N/A 16100-GEL-702  PA42A-C  ’00-05 XR50R, CRF50F
o8 000001  N/A 16100-GEL-A21  PA42???   ’06 CRF50F
o# abcde f price  Honda part#     gaskets
o1 111111 $32 16010-181-831  gasket solo-set   o0 1f 1g 1h 1l
o1 111111 $32 16010-181-305  gasket multi-set 1a 1f 1g 1h 1l
1f  111111 $21 00000-000-000  float bowl gasket  Ø1.5 NC50-type
1g 111111 $$2 00000-000-000  drain plug o-ring 1.5 x 4 (7 od)
1h 111111 $$2 00000-000-000  intake o-ring 2 x 18 (22 od)
1l   111111 0$4 16110-181-831  top rubber washer 13 x 18.5 x 1
o# abcde f price  Honda part#     parts list
02 110000  N/A 16012-GW8-671 needle set
02 001100  N/A 16012-GW8-680 needle set
02 000010  N/A 16012-GEL-701  needle set
02 000001  N/A 16012-GEL-A21  needle set
03 111111 $28 16013-147-004  float set oo 3b 3c 3d
04 111111  N/A 16015-099-691  chamber set
05 100000  N/A 16016-GW8-671
05 111100  N/A 16016-GW8-672 screw set idle air
05 000011  N/A 16016-GEL-701  screw set idle air
06 111110  N/A 16022-GW8-671
06 111111  N/A 16022-GW8-672 slide set
07 111111  N/A 16028-GC8-004 idle speed screw set
09 111111  N/A 16014-181-831  top set M20-1.0 w/clip for cable pipe
10 111111 $22 16155-883-005  float needle valve
11 222222 0$1 93892-04012-08 screw & washer M4x12 pan phillips
14 110000  N/A 99101-187-0550 main jet screw-in #55  4 001111 0$7 99101-187-0580 main jet screw-in #58 

Z50 Model History

’61-63 Z100
’64-78? CZ100
’68-78 Z50A US
’79-86 Z50R US
’79- Z50G AU Ex DE
Z50GZ AU Ex DE SA
’79- Z50J AU Ex FI DE SA SW
’82-96 Z50J FI
’85 Z50J DE
’92-93 Z50J Ex
’04-14 Z50J JP
’88 Z50J1 JP AU FR Ex DE
’89 Z50J2 FI
’89 Z50J2 JP
’90 Z50J3 FI
’90-00 Z50J3 4 5 6 B C E F H J L M N P S T V W X Y Z Japan
Z50JC D E H Z Finland
Z50J

Service: Here is a good article about how to remove and clean the non-replaceable idle (pilot) jet.

https://thumpertalk.com/forums/topic/1047667-clogged-pilot-jet-on-a-crf50-success/

The CRF50F idle jet in that article did not crush when gripped lightly with a vise grip pliers. But some pressed-in idle jets have thin walls, or have a tighter fit that needs heavy clamping. Those require a close-fitting drill bit or solid wire, be placed in the hole first, to prevent crushing the tube with the vise grips. It’s a good idea to do that always. 

Contents
19. Float needles
20. Float bowls
21. Gaskets and O-rings
22. Jets 

19.  Float needles (valves)

Baby valves: These are the float needle valves for the smallest “baby” Keihin carburetors. Most other float needles are bigger than these, but look the same in photos.

16123-063-004 float needle valve $13  all metal type
On road models: 1969-70 Honda PC50, 1969-70 Honda PS50, 1970-72 Honda PC50K1, 1971-73 PF50 Amigo standard (FR DK NE), 1971-73 PF50 Amigo Graduate (UK), 1970-71 PS50K1, PS50K1 (NE), others

16011-881-741 float needle valve  N/A stirrup type, 3-sided for 4.00 hole
supersedes 16011-143-620, 16011-147-004
On road models: 1977-79 Honda NC50 Express (with PA08B-A carb), 1978-79 PA50I and PA50II Hobbit, 1976-78 Z50A Mini Trail  Off road: 1976-78 Honda Z50A, 1977-79 XL75, 2004-07 CR80F, 1976-78 XR75, 1979-84 XR80, 1985-03 XR80R, 1977 CT125, 1976 TL125

16155-883-005 float needle valve $22 regular type, 3-sided for 4.00 hole
On road models: 1973-77 Honda PC50K1, 1973-78 Honda PF50 Amigo/Novio, 1978-83 Indian AMI-50, 1979-83 Honda NC50 Express (with PA08B-B carb), 1980-83 PA50II Hobbit, 1979-81 NA50 Express II, 1981-82 NX50 Express SR, 1982-83 NU50 Urban Express, 1980-83 C70 Passport, 1978-79 CT90 Trail 90, 1986 CT110 Trail 110, 1982 MB5, 1990 NS50, 1984-85 NQ50 Spree, 1988-90 SA50 Elite 50, 1985-91 CH80 Elite 80  Off road: 1979-99 Honda Z50R, 1988 ZB50, 2000-03 XR50R, 2004-12+ CRF50F, 2004-09, CRF70F, 1978-82 CT70, 1997-03 XR70R, 1978-79 Honda CT90, 1980-84 CT110

Valve seats: The seat is the hole that the needle tip seals against. These “baby” Keihin PA series carbs have non-replaceable valve seats. Most motorcycle carburetors have replaceable float valve seats that screw in or push in. The seat is normally replaced with the needle. With these the seat must be cleaned, polished and inspected. It’s a tiny round hole at the end of a dark small round tunnel. It’s hard to see. It must be perfectly circular with no nicks or scratches on the edge of the hole, where it seals against the rubber cone tip of the needle.  The walls of the tunnel must be clean, smooth and shiny or the float might stick open a little and cause an overflow leak.

Beware of low cost float needles (valves). These have to be made precisely the same as originals in order to function properly. In the photo, the left one is a 16011-991-741 generic low-cost replica, made incorrectly. The stirrup wire is bent and the needle is longer. The right and middle are 16011-991-741 Honda originals (or KL-made replicas) for comparison, made correctly. 

20. Float Bowls for “baby” Keihin

Chamber families 165, 147A, 191, GK8

Here the chamber sets from above are all listed together, along with the carbs and bikes they go on. A chamber set includes the float bowl, float gasket, drain screw, and drain screw o-ring. As a courtesy, here are the links to CMS in Netherlands where you can view their image and see their price and availability.

Families: A chamber set family is one or more chamber sets that can interchange.

Jet pad: Before about 1980 these carburetors had push-in main jets. The push-in main jet was supported by a pill size rubber pad. The jet pad was held by a circular wall in the bottom of the float bowl. You can see that in the image on the right. The second bowl is for a jet pad, but the first bowl is not.

Choke jet: Carbs with fuel enrichment  type chokes have a jet in one corner of the float bowl (2nd, 3rd, and 4th in the image). Carbs with air valve choke plates do not have a choke jet (first in the image).

  Float Bowls (chambers) with no choke jet  =================    chamber     gasket

16015-064-004                                064 family
cmsnl.com roundish shape, shallow for jet pad, no choke jet
on carbs C4A C5A C5B F4A F5A lever-plate choke
on bikes 69-70 PC50/PS50, 70-73 PC50K1/PS50K1, 71-73 PF50

16015-114-004                                114 family
cmsnl.com roundish shape, deep for jet pad, no choke jet
on carbs 655A 674A lever-plate choke
on bikes 72-75 Z50, 70-75 QA50

16015-081-004                                081 family
cmsnl.com NC50-shape, shallow for jet pad, no choke jet
on carbs PA00A PA01A lever-plate choke
on bikes 73-77 PF50R, 73-78 PC50K1

16015-130-640  
 cmsnl.com NC50-shape, shallow, for jet pad, no choke jet
on carbs PA03AA lever-plate choke
on bikes 76-78 Z50A, 79-81 Z50R and other Z50’s

16015-099-691                                165 family
cmsnl.com NC50-shape, shallow, for no jet pad, no choke jet
on carbs PAM0A PA03HA PA03HB PA03MA others lever-plate choke
on bikes 78-83 Indian, 88-99 Z50R, 04-05 CRF50F many others

16015-130-641 ⇒ 16015-165-621
 cmsnl.com NC50-shape, shallow, for no jet pad, no choke jet
on carbs PA03CA PA03DA lever-plate choke
on bikes 80-85 Z50R

same

16015-165-920 ⇒ 16015-165-621
 cmsnl.com NC50-shape, shallow, no jet pad, no choke jet
on carbs
on bikes

16015-165-621 ⇒ 16015-165-B10
 cmsnl.com NC50-shape, shallow, for no jet pad, no choke jet
on carbs PA03FB lever-plate choke
on bikes 86-87 Z50R

same

16015-165-B10
 cmsnl.com NC50-shape, shallow, for no jet pad, no choke jet
on carbs PA03?? lever-plate choke
on bikes 93-96 Z50J (Japan model)

  Float Bowls (chambers) with choke jet  =================    chamber     gasket

16015-147-004                                147A family
  cmsnl.com NC50-shape, shallow, for jet pad, with choke jet
on carbs PA08BA  black float, cable-enrich choke
on bikes 77-78 NC50

16015-147-014                                 147B family
 cmsnl.com  NC50-shape, shallow, for no jet pad, with choke jet
on carbs PA08BB 08EA 08EB 08DA white float cable-enrich choke
on bikes 78-80 NC50, 79-80 NA50

same

16015-187-043 use 16015-191-034  191 family
 cmsnl.com NC50-shape, deep, for no jet pad, with choke jet
on carbs PA13EA                 white float vacuum-enrich choke
on bikes 82-83 NU50, NU50M

16015-187-671 use 16015-191-034
 cmsnl.com NC50-shape, deep, for no jet pad, with choke jet
on carbs PA13BA                 white float vacuum-enrich choke
on bikes 81-82 NX50

16015-191-014 ⇒ 16015-191-024
 cmsnl.com NC50-shape, deep, for no jet pad, with choke jet
on carbs PA15AA PA16AA  white float vacuum-enrich choke
on bikes 81 NC50, 81 NA50

same

16015-191-024 ⇒ 16015-191-034
 cmsnl.com NC50-shape, deep, for no jet pad, with choke jet
on carbs PA15AA PA16AA  white float vacuum-enrich choke
on bikes 81 NC50, 81 NA50

16015-191-034   available soon
  cmsnl.com NC50-shape, deep, for no jet pad, with choke jet
on carbs PA15AA PA16AA  white float vacuum-enrich choke
on bikes 81 NC50, 81 NA50

16015-GA6-671 use 16015-191-034
treatland.tv NC50-shape, deep, for no jet pad, with choke jet
on carbs PA13EA                 white float vacuum-enrich choke
on bikes 82-83 NC50

16015-GK8-671                                GK8 family
  cmsnl.com  NC50 with outer loop, very deep, choke jet
on carbs PA29CD PA29HA others electric-enrich choke
on bikes 84-86 NQ50, 83-85 NM50

21.  Gaskets

There are 100’s of vintage Honda carburetors. Many share the same gaskets, but have maybe one or two things different. To reduce the number of different gasket sets, Honda combines several sets into one multi-set. In a multi set there are extra “optional” gaskets, that may or may not be needed. These are in separate packages labeled A or B. There is a sheet of paper with a table of replacement gasket set part numbers, the specific part numbers they replace, and a number, usually 1 or 0, in the A and B columns, telling how many of each “optional” gaskets are required.  

Multi-App Sets (for several carburetors)

16010-114-305 $34
fits 1972-75 Honda Z50A (minus 2 x 18 o-ring)
fits 1970-72 Honda QA50
fits 1970-73 Honda PC50K1
1p top rubber washer 10 x 15 x 1  
1q (A) drain screw washer 3 x 6 x 0.5
1d main jet o-ring 1 x 3 (5 od)
1e jet support disk Ø7.5 x 1.7 
1n float bowl gasket 1.5 x 40 (43 od) 
1r drain plug o-ring 2 x 4 (8 od)

16010-143-305 $37    
fits 1976-78 Z50A Mini Trail, 1979-81 Z50R  
fits ’77 NC50 and some ’78-79 (except drain plug o-ring)
fits 1973-77 PC50K1 
fits 1978-80 Indian AMI50 (except drain plug o-ring)
1a top rubber washer 10 x 18 x 1
1h (A) intake o-ring 2 x 18 (22 od) 
1c (B) intake o-ring 2 x 20 (24 od) 
1d main jet o-ring 1 x 3 (5 od)
1s jet support disk Ø7.5 x 1.8 
1f  float bowl gasket Ø1.5 NC50 type
1i  drain plug o-ring 2 x 2.5 (6.5 od)

16010-147-505 $31 
fits 1979 NC50 and some 1978
fits 1979-80 NA50 and NC50
fits 
1b top rubber washer 13 x 16.5 x 1
1c intake o-ring 2 x 20 (24 od)
1d (A) idle fuel screw o-ring 1 x 3 (5 od)
1g (A) drain plug o-ring  1.5 x 4 (7 od)
1f  float bowl gasket Ø1.5 NC50 type
1i  (B) drain plug o-ring 2 x 2.5 (6.5 od)

16010-156-305 $24   
fits 1978-83 Honda PA50
1c intake o-ring 2 x 20 (24 od)
1w intake o-ring 2.5 x 24 (29 od)
1g drain plug o-ring  1.5 x 4 (7 od)
1j float bowl gasket 2 x 50 (54 od)

 
16010-181-305 $32  
fits 1979-86 Z50R, 2000-03 XR50R, 2004-11+ CRF50F
1a top rubber washer 10 x 18 x 1
1h intake o-ring 2 x 18 (22 od)
1l  top rubber washer 13 x 19 x 1 
1g drain plug o-ring  1.5 x 4 (7 od)
1f float bowl gasket Ø1.5 NC50 type

16010-GE8-315 $27  
fits 84 NB50M, 82-85 NJ50M, 84-86 NQ50, NQ50M
1b top rubber washer 13 x 16.5 x 1
1c intake o-ring 2 x 20 (24 od)
1x (A) o-ring 1 x 12.5 (14.5 od)
1z (B) o-ring 1 x 16 (18od)
1g drain plug o-ring  1.5 x 4 (7 od)
1v float bowl gasket 2.5 tall x 1.5 with loop

 
16010-GF8-305 $32  
fits 1981-82 NX50, 1982-83 NU50
1b top rubber washer 13 x 16.5 x 1
1h intake o-ring 2 x 18 (22 od)
1d (A) idle fuel screw o-ring 1 x 3 (5 od)
1t  (B) o-ring 1.5 x 8.5 (11.5 od)
1u (B) nylon washer 6.2 x 11 x 0.8
1g drain plug o-ring  1.5 x 4 (7 od)
1k float bowl gasket 2.5 tall x 1.5 wide NQ50 type

Individual Gaskets

# price  part# or sect#  Gaskets and Seals
a $$3 6.1.1a  000000 rubber washer 10 x 18.5 x 1
b $$8 6.1.1b  000000 rubber washer 13 x 16.5 x 1
c  $$2 6.1.2  0000000 o-ring 2.0 x 20  (24 od)
d 0$2 16176.551.004 o-ring 1.0 x 3    (5 od)
e  $14 16197.063.004 jet pad disk 7.3 x 1.75
f  $21 6.1.5  0000000 float gasket 1.5 x 1.5 70’s type
g $$2 6.1.6  0000000 o-ring 1.5 x 4    (7 od)
h $$2 6.1.7  0000000 o-ring 2.0 x 18  (22 od)
i   0$2 16175.260.004 o-ring 2.0 x 2.5 (6.5 od)
j   $11 6.1.9  0000000 o-ring 2.0 x 50  (54 od)
k $25 8.1.3  0000000 float gasket 2.5 x 1.5 80’s type
l  0$4 16110.181.831  rubber washer 13 x 18.5 x 1
m N/A 11.1m 0000000 float o-ring 2.0 x 49
n 0$2 16174.044.004 o-ring 1.5 x 40  (43 od)
o   $3 5.1.1o  000000 o-ring 1.5 x 5    (8 od)
p 0$5 16171.044.004 rubber washer 10 x 15 x 1
q $$2 17.1q 0000000 fiber washer 3 x 6 x 0.5
r  0$5 16175.001.004 o-ring 2.0 x 4    (8 od)
s  $14 6.1.1s  000000 jet pad disk 7.3 x 1.85
t    $2 17.1t  0000000 o-ring 1.5 x 8.5 (11.5 od)
u $$2 17.1u 0000000 nylon washer 6.2 x 11 x 0.8
v $20 8.1.1v  000000 float gasket  2.5 x 1.5 with loop
w   $3 17.1w 0000000 o-ring 2.5 x 24  (29 od)
x N/A  8.1.1x  000000 o-ring 1.0 x 12  (14 od)
y  N/A 16189.056.004 seal washer 6 x 8 x 0.5
z  0$2 8.1.1z  000000 o-ring 1.0 x 16  (18 od)

Left is Oreo cookie “e” from set 16011-114-305, 1.75 mm thick.
Right is Oreo cookie “s” from set 16011-143-305, 1.85 mm thick.

Individual Gaskets a to z Contained in Gasket Sets

Multi-sets are red. They have extra gaskets for other applications.
Solo-sets are black. They only have the gaskets that are needed.

a b c d e f g h i j k l n o p q r s t u v w x z   gasket set #   price  carbs .
a b c d e f g h i j k l n o p q r s t u v w x z 16010-044-680 $14 50B
a b c d e f g h i j k l n o p q r s t u v w x z 16010-114-305 $34
a b c d e f g h i j k l n o p q r s t u v w x z 16010-114-004 $34 655A 674A
a b c d e f g h i j k l n o p q r s t u v w x z 16010-063-000 $32 C5B
a b c d e f g h i j k l n o p q r s t u v w x z 16010-063-004 $32 C4A,4B,5A F4A,5A

a b c d e f g h i j k l n o p q r s t u v w x z 16010-122-305
a b c d e f g h i j k l n o p q r s t u v w x z 16010-122-004 N/A  PA06A,07A
a b c d e f g h i j k l n o p q r s t u v w x z 16010-131-004 N/A  006A

a b c d e f g h i j k l n o p q r s t u v w x z 16010-143-305 $37
a b c d e f g h i j k l n o p q r s t u v w x z 16010-143-620 $35 PA08BA
a b c d e f g h i j k l n o p q r s t u v w x z 16010-081-004 $31 PA00A 01A 03A
a b c d e f g h i j k l n o p q r s t u v w x z 16010-081-014 $29 PA03BA 03CA

a b c d e f g h i j k l n o p q r s t u v w x z 16010-147-505 $31
a b c d e f g h i j k l n o p q r s t u v w x z 16010-147-711 $30 PA08BB,EA,EB,DA
a b c d e f g h i j k l n o p q r s t u v w x z 16010-147-004 $30 PA08BB,EB

a b c d e f g h i j k l n o p q r s t u v w x z 16010-156-305 $24
a b c d e f g h i j k l n o p q r s t u v w x z 16010-124-760 $23 BB21AB,F 20AC,F

a b c d e f g h i j k l n o p q r s t u v w x z 16010-181-305 $32
a b c d e f g h i j k l n o p q r s t u v w x z 16010-181-831 $33 PA03DA,FB

a b c d e f g h i j k l n o p q r s t u v w x z 16010-GE8-315 $27
a b c d e f g h i j k l n o p q r s t u v w x z 16010-GE8-305 $27 PA29CB,CD,DA,DB

a b c d e f g h i j k l n o p q r s t u v w x z 16010-GF8-305 $32
a b c d e f g h i j k l n o p q r s t u v w x z 16010-187-003 $30 PA12A 13BA 13EA
a b c d e f g h i j k l n o p q r s t u v w x z 16010-190-004 $29 PA15A 16A 13BB 25A

22. Jets

5 x 9.5 Push-in price  size   carbs     models
99114.063.0550 none  55 C4A, C4B ’69-70 PC50 40km/h
99114.063.0550 none  55 S4A, S4B ’69-70 PS50 40km/h
99114.063.0550 none  55 F4A         ’72-73 PF50, PC50K1 40km/h
99114.063.0580 $16    58 S5B         ’70-71 PS50K1
99114.063.0620 none  62 C5A, C5B ’69-70 PC50 50km/h
99114.063.0620 none  62 S5A, S5B ’69-70 PS50 50km/h
99114.063.0620 none  62 F5A         ’72-73 PF50, PC50K1 50km/h
99201.122.0650 none  65 PA 06A    ’73-75 PM50, ’73-78 PF50M
99201.122.0750 none  75 006A       ’74-75 MR50
99201.122.0750 none  75 PA 07A    ’75-78 PF50M 50km/h
5 x 8.5 Push-in price  size   carbs     models
99201.081.0550 none  55 PA 02A    ’74-75? Z50J1 Germany
99201.081.0580 $16    58 PA 03A    ’76-78 Z50A
99201.081.0650 $22    65 PA 01A    ’73-77 PC50K1 40km/h
99201.081.0700 $22    70 PA 00A    ’73-77 PC50K1 50km/h
99201.081.0780 $23    78 PA 08B-A ’77-79 NC50 #70 drilled to 78
5 x 15? Push-in price  size  carbs      models
99201.114.048   none  48 674A       ’70-75 QA50
99201.114.052   none  52 655A       ’72-75 Z50A
99201.114.055   none  55 655A       ’72-75 Z50A

1. 99101-187-0700, 2. 99101-124-0700

M6-0.75 Screw-in $ size  carb      models .
99101.187.0580 0$7 58 PA03DA ’82-85 Z50R
99101.187.0580 $00 58 PA03FB  ’86-87 Z50R
99101.187.0680 0$7 68 PA29CD ’85 NQ50
99101.187.0680 $00 68 PA29HA ’83-85 NB50
99101.187.0700 $$7 70 PAMOA  ’78-80 Indian
99101.187.0700 $00 70 PA25A?  ’82-83 NC50I
99101.187.0750 0$7 75 PA15A   ’81 NC50
99101.187.0750 $00 75 PA16A   ’81 NA50
99101.187.0750 $00 75 PA13BB ’82-83 NC50
99101.187.0760 0$7 76
99101.187.0780 0$7 78 PA13BA ’81-82 NX50
99101.187.0800 0$7 80
99101.187.0850 0$7 85 PA13EA ’82-83 NU50, NU50M

M7-0.75 Screw-in $ size  carb      models .
99101.124.0600   $7 60 BB21A   ’78-79 PA50 I  (20mph)
99101.124.0780   $7 78 BB20A   ’78-83 PA50 II (30mph)

23. Carb Tops

Top Sets M16 with 10 x 15.0 rubber
16014-044-004  N/A metal w/adjuster, boot sold separate
’66-67 P25, ’67-68 P50
16014-064-004  N/A metal, short pipe, boot sold separate
’69-70 PC50, PS50, ’70-73 PC50K1, PS50K1, ’72 PF50
16014-120-004  N/A metal, short pipe w/adjuster
’70-75 QA50, ’72-75 Z50A

Top Sets M20 with 10 x 18.5 rubber
16014-081-004 $30 metal w/adjuster, boot sold separate
’73-77 PC50K1, ’73-78 PF50R, ’78-81 Indian AMI-50
16014-143-620 $29 metal no adjuster, boot sold separate
’77-80 NC50 PA08B-A

Top Sets M18 with 13 x 16.5 rubber
16014-147-004 $36 plastic w/adjuster, boot sold separate
’77-80 NC50 PA08B-B, ’79-81 NA50
16014-147-014 $36 metal  w/adjuster, boot sold separate
’79-81 NA50
16014-187-013  N/A metal w/very long pipe, with boot-cover
’81-82 NX50, ’82-83 NC50
16014-190-014  N/A metal w/fixed pipe no cover
’81 NC50
16014-GC6-003
16014-065-921  N/A metal no adjuster, no cable pipe
’81 NCZ50
16014-GB2-003
16014-GB0-831
16014-098-980  N/A metal w/fixed pipe
’82-83 NU50

Top Sets M20 with 13 x 18.5 rubber
16014-000-000 $32 metal w/adjuster, no boot groove
1
16014-165-622  N/A metal w/short pipe
’79-85? Z50J, G, GZ
16014-181-831  N/A metal w/pipe clip, boot sold separate
’88-99 Z50R, ’00-03 XR50R, ’04-06 CRF50F

16014-GB1-901  .
16014-GB1-951  .
16014-GB5-941  .
16014-GB6-610  N/A metal

16014-GB1-912

Where else to get Keihin parts

Consolidated Motor Spares B.V. (CMS): This is an excellent online store from the bike-loving nation of Netherlands that has “every” Honda part. They have parts schematic illustrations for every Honda model worldwide, and photos of every part on every Honda, and not just motorcycles. And not just Honda, but also Kawasaki, Suzuki, and Yamaha. Much of the information of the Honda “Baby” Keihin carburetors came from CMS. https://www.cmsnl.com/ 

Contents
carburetor     years    Honda model
3. PA 00A-A  ’73-77 PC50K1, PF50R
3. PA 01A-A  ’73-77 PC50K1, PF50R
3. PA M0A-A  ’78-81 Indian AMI50
4. BB 21A-B  ’78-78 PA50-I Hobbit
4. BB 21A-F  ’79-79 PA50-I Hobbit
4. BB 20A-C  ’78-78 PA50-II Hobbit
4. BB 20A-F  ’79-83 PA50-II Hobbit
5. P 006A-A  ’74-75 MR50 Elsinore
5. PA 06A-A  ’73-78 PM50, PF50M
5. PA 07A-A  ’75-78 PF50M

3. Keihin

#  size  carb   years  code km   models
a 0∅9 PA 01A  ’73-77 081 40 Honda PC50K1
a 0∅9 PA 01A  ’73-78 099 40 Honda PF50R Amigo/Novio
b ∅10 PA 00A  ’73-77 081 50 Honda PC50K1
b ∅10 PA 00A  ’73-78 099 50 Honda PF50R Amigo/Novio
c ∅10 PA M0A ’78-81 000 50 Indian AMI-50 (US)

  
1. ’73 Honda PC50K1, 2. ’80 Indian AMI-50 (US), 3. ’73-78 Honda PF50 Amigo line

   
1. ’75 Honda PC50K1, 2. ’80 Indian AMI-50 (US), 3. Keihin PA-00A carb, 4. Missing the jet pad #1e.

 
1. #0 16100-081-024 Keihin PA-00A carb, 2. #0 Keihin PA-M0A carb

Late PC50: In 1973 the PC50 carburetor changed from “donut” float to a swinging float, and a NC50-type float bowl and gasket. The 1973-77 PC50K1 and 1973-78 PF50 engine and carb are the same as the Taiwan remake engine and Keihin carburetor used on the 1978-83 Indian moped. So the carburetor parts are the same also, with some exceptions.

PA 00A (16100-081-024) and PA 01A (16100-099-693) have the same parts. The push-in jet size, venturi size and intake flange o-ring are the only difference. 

PA M0A (E210-20-50) has the same parts as PA 00A and PA 01A, except for 1) a screw-in jet instead of push-in, 2) no jet pad, 3) no jet pad holder in float bowl, 4) a white regular type float instead of a black stirrup type. 

Flange Mount: 32 mm hole spacing, 2 x 18 (22 od) o-ring 00A, 01A.

Indian AMI50: The Indian AMI50 Chief four stroke moped engine, OHV with pushrods and internal pedals, made from 1978-1984, is a Taiwan-made copy of a Honda PC50K1 or PF50 engine, OHV with pushrods and internal pedals, made from 1973-1978. The Indian had three different carburetors, Tillotson (some 1978), Keihin (some 1978, most 1979-80), Mikuni (some 1980, all 1981-84). Only the Keihin parts are listed here.

1. left, #0 Keihin PA-M0A carb, 2. right, #0 generic PA-M0A carb

   
1. #1  16010-081-004 carburetor gasket set for PA 00A and 01A
2. #1  16010-081-014 carburetor gasket set for PA M0A
3. #1  16010-181-305 carburetor multi-set for PA M0A, 03C, 03D, 03E, 03F

0# abc  price  Honda part#     carburetor   
00 100  N/A 16100-081-024 PA 00A Ø10 E10
00 010  N/A 16100-099-693 PA 01A   Ø9 E10
00 001  N/A 00000-000-000 PA M0A Ø10
00 111 $75 16100-000-000 generic Ø10, jet 70 screw-in
00 111 $50 16100-000-000 generic no top, slide, needle
0# abc  price  Honda part#
01 110 $35 16010-081-004 gasket solo-set   1a o d e f g h
01 oo1 $25 16010-081-014 gasket solo-set   1a o o o f g h
01 001 $32 16010-181-305 gasket multi-set 1a o o o f g h i  l
1a 111 $$3 00000-000-000 top rubber washer 10 x 18.5 x 1
1c 000 $$2 00000-000-000 intake o-ring 2 x 20 (24 od) 
1d 110 0$2 16176-551-004 main jet o-ring 1 x 3 (5 od)
1e 110 $14 16197-063-004 jet pad disk Ø7.5 x 1.8 
1f  111 $21 00000-000-000 float bowl gasket Ø1.5 NC50-type
1g 001 $$2 00000-000-000 drain screw o-ring 1.5 x 4 (7 od)
1h 110 $$2 00000-000-000 intake o-ring 2 x 18 (22 od)
1i  110 0$2 16175-260-004 drain screw o-ring 2 x 2.5 (6.5 od)
02 110  N/A 16011-881-741 float needle valve  stirrup type
02 001 $22 16155-883-005 float needle non-stirrup type
03 111  N/A 16012-081-014 needle set 3a 3b 3c 3d
3a 111 $10 00000-000-000 jet needle D348 thick Ø2 x 33
3b 111 0$2 16157-044-004 needle e-clip substitute 1.5mm
3c 111 0$5 16156-044-004 w-spring clip
3d 111  N/A 16133-081-004 needle jet ∅3.95 ∅5 ∅3.9 ∅5 x 27
3d 000 0$6 00000-000-03A needle jet ∅3.95 ∅5 ∅3.9 ∅5 x 27
3d 000 0$6 00000-000-03B needle jet ∅3.95 ∅5 ∅3.9 ∅5 x 27
o4 110  N/A 16013-099-691 float set black 4c 4d 4e PA 00A, 01A
4a 001 $28 16013-147-004 float set white 4b 4d 4e PA M0A
4b 001 $21 00000-000-000 float bare white non-stirrup
4c 110  N/A 00000-000-000 float bare black stirrup
4d 111 $$4 00000-000-000 hinge pin substitute Ø2 x 18.5
4e 111 $$3 0-93600-04006 hinge pin screw M4 x 6 sunk
05 111 $30 16014-081-004 top set 5a 5b 1a
5a 111 00000-000-000 substitute cap brass M20-1.0
5b 111 0$3 00000-000-000 cable adjuster male M6-0.75
06 110  N/A 16015-081-004 chamber set 6a 6b 1f 1i
6a 110  N/A 16015-165-B10 float bowl bare for push-in jet
06 001 $67 16015-099-601 chamber set 6a 6c 1f 1g
6a 001 $46 16015-165-B10 float bowl bare for screw-in jet
6b 110  N/A 00000-000-000 bowl drain screw M4-0.70
6c 001 $16 00000-000-000 bowl drain screw M6-1.00
07 111 $15 16016-143-620 adjustment screw set 7a 7b 7c 7d
7a 111 $$9 00000-000-000 idle air mix screw M6-0.75 special
7b 111 $$4 00000-000-000 idle speed screw M4-0.70 special
7c 111 $$7 00000-000-000 idle air screw spring Ø4.9 x 10
7d 111 $$2 00000-000-000 idle speed screw spring Ø5.6 x 10
08 101 $34 16022-081-004 valve set 8a 8b Ø13 PA 00A
08 101 $00 16022-HB2-003 new #
8a 101 $22 00000-000-000 throttle slide Ø13 #15A PA 00A
8b 101 $12 00000-000-000 throttle spring Ø10 x 42 PA 00A
08 010  N/A 16022-143-620 valve set 8a 8b Ø12 PA 01A
08 010 $00 16022-191-004 new #
11 111 0$2 16118-086-004 rubber boot substitute Dellorto
12 222 0$1 0-93500-04012 bowl screw M4 x 12 pan phillips
13 222  .25 0-95002-02070 bowl screw lock washer
14 111  N/A 0-95001-35150 drain hose
15 111  N/A 0-95002-02070 drain hose clamp
16 001 $$7 99101-187-070 main jet #70 M6-0.75 screw-in
16 001  N/A 99201-187-0700 new #
16 110 $22 99201-081-070 main jet #70 0.0275″ push-in
16 110  N/A 99201-081-0700 new #
17 001  N/A 00000-000-000 carb body bare
18 001  N/A 00000-000-000 idle jet press-in tube 0.38 mm=0.015″

1. Indian PA MOA, 2. PA MOA parts, 3. needle jets

Choke plate: These three carbs have a lever choke that swings a plate to block air flow. There is no enrichment fuel path or jet. So the float bowl has no choke jet. The other baby Keihins with cable or vacuum operated choke do have a choke jets in their float bowls. The choke (enrichment) fuel passes up through the sealed off corner of the bowl gasket.  

Float Bowl: The PA-03A and 03B chamber set (float bowl, float bowl gasket, drain screw and drain screw o-ring) from 1970’s Honda mini-cycles (Mini Trail or Monkey) interchanges with a PA 00A, 01A chamber set  from 1970’s Honda mopeds. The drain screw (4 or 6 mm) and its o-ring (2×2.5 or 1.5×4) are different. So if the float bowl is changed the drain screw must also be changed. 

Needle jet: The PA-03A and 03B mini-cycle needle jets (emulsion tubes) interchange with PA 00A, 01A, and M0A moped ones. These press out with taps from a hammer and punch from above. At first the punch tip needs to be bigger than the 4 mm tube end. Once the tube end gets below the floor a smaller 3.5 to 3.9 mm straight round bar is needed. It has to enter the 4 mm hole and contact the idle tube around the edge.

Idle jet: A little downstream from the needle jet is the idle jet. It is a pinhole 0.015″ at the upper end of a vertical brass tube about 20mm long. The idle tube is a press fit in the carb body. Some can be pulled out with just a pliers. Some might be tighter and require a drill bit be placed inside the tube to prevent crushing from the tighter pliers grip. This tube was never intended to be replaced and is not sold or included in any common carb kit. 

Air tunnels: In the front below the main air inlet are two small horizontal air tunnels. The center tunnel is main air and the side tunnel is idle air. The small amount of air sucked in through the main air tunnel passes through tiny holes in the emulsion tube and becomes thousands of microscopic air bubbles in the liquid gasoline that is being drawn upward. The tiny amount of air sucked in through the idle air tunnel passes around the idle air adjustment screw cone shape tip and goes to the vertical idle passage just above the idle jet. The idle air tunnel is the size of a regular paper clip 0.036 inch. A straightened paper clip cleans it perfectly.    

4. Keihin

#  size 0 carb 00 years code mph   US models
a  ∅10 BB 21A-B ’78-78 148  20 PA50 I  Hobbit
b  ∅10 BB 21A-F ’79-79 148  20 PA50 I  Hobbit
c  ∅12 BB 20A-C ’78-78 148  30 PA50 II Hobbit
d  ∅12 BB 20A-F ’79-83 148  30 PA50 II Hobbit

1. ’78 PA50II, 2. ’78 PA50I, 3. ’83 PA50II, 4. PA50 speed versions

1. Keihin BB 21A-B, 2. Keihin BB21A-F

1. Keihin BB 20A-C, 2. 16010-124-760, 3. 16010-156-305

Flange mount: 42 mm bolt hole spacing

Honda’s successor to the four-stroke PC50 was the two-stroke PA50, known in the USA as Hobbit, and in Europe as Camino. It was made in Belgium by Honda Benelux, so it had a mix of Japanese and European design and componentry. 

In US models, 20 mph versions were 1978-79 red. 30 mph versions were 1978-79 yellow, 1980 yellow, 1981-82 red, and 1983 black.

This Keihin BB type carburetor is not like any other moped carburetor. It looks more like a Honda generator carburetor. It is a very flat design. It has to be special because it swings up and down with the engine, and is very close to the frame at the place where you step through.  The BB type floats on PA50 are wider and flatter than NC50 or Z50 floats.  

 
o# abcd price  Honda part#    carburetor
00 1o00  N/A 16100-148-645 21A-B ∅10 20 mph 1978 
00 01o0  N/A 16100-148-646 21A-F ∅10 20 mph 1979
00 0010  N/A 16100-148-708 20A-C ∅12 30mph 1978
00 0001  N/A 16100-148-708 20A-F ∅12 30mph’79-83
o# abcd price  Honda part# 
01 1111 $14 16010-124-760 gasket solo-set   1c 1g oo 1j
01 1111 $24 16010-156-305 gasket multi-set 1c 1g 1w 1j
1c 1111 $$2 00000-000-000 intake o-ring 2 x 20 (24 od)
1g 1111 $$2 00000-000-000 drain screw o-ring 1.5 x 4 (7 od)
1j  1111 $11 00000-000-000 float bowl gasket 2 x 50 (54 od)
o2 1010  N/A 16011-147-004  16011-147-305
o2 1010  N/A 16011-881-741 float needle stirrup type
o2 0101 $22 16011-883-005 float needle regular type
03 1010  N/A 16013-124-760
03 1010  N/A 16013-124-762 float set black 3a 3c 21A-B, 20A-C
03 0101  N/A 16013-883-305 float set white 3b 3c 21A-F, 20A-F?
3a 1010  N/A 00000-000-000 float bare black stirrup type
3b 0101  N/A 00000-000-000 float bare white regular type
3c 1111  N/A 00000-000-000 hinge pin ∅2 x 23
04 1111  N/A 16016-148-611 screw set
04 1111  N/A 16016-890-015 screw set 4a 4b 4c 4d 4e
4a 1111 0$1 00000-000-000 idle speed screw M4 x 15 slot
4b 1111  N/A 00000-000-000 idle speed spring
4c 1111  N/A 00000-000-000 idle fuel screw
4d 1111  N/A 00000-000-000 idle fuel spring
4e 1111 0$3 00000-000-000 cleaning access plug M5 x 5 slot
05 1111  N/A 16024-124-760 drain screw set
07 1111  N/A 16110-148-010 choke lever cover
08 1111  N/A 16166-148-740 nozzle, main
09 1111  N/A 16199-148-611 vent hose ∅3.5 ∅6.5 x 65 gray
09 1111  .50 16199-148-sub substitute  ∅3.1 ∅6.3 x 65 clear
10 1111 0$2 0-93500-04008 cable pinch screw M4 x 8
11 2222 0$1 0-93500-04012 bowl screw M4x12 pan phillips
12 2222  .50 0-94111-04800 lock washer M4 split
13 1111  N/A 95001-35400-40 drain hose ∅3.5 ∅7.0 x 400 gray
13 1111 0$1 95001-35400sub substitute ∅3.1 ∅6.3 x 400 clear
14 1010 0$7 99101-124-600 main jet 60 21A
14 0101 0$7 99101-124-780 main jet 78 20A
15 1111  N/A 0-95002-02070 drain hose clamp B7 (for 7 not 6.3)
16 1111  N/A 0-95002-02065 vent hose clamp B6.5

PA50 carb removal

 Servicing: The best way to remove the PA50 carburetor is to hold the back of the bike up by either a rope tied to an overhead beam, or with a milk crate and blocks of wood. Remove the floorboards and side covers. Unplug the ignition wires from the coil at the right rear. Pull them through and move them out of the way. Disconnect the decompression cable and the spark plug cap. Loosen the wiring clamps so there is slack in the wires. Remove the lower rear shock bolts and the swing arm pivot bolt above the engine. Then the whole sub-frame can be moved away from the main frame, either by lifting the back of the bike up, or by swinging it around sideways.

Note that the float bowl can go on two different ways. The wrong way assembles normally, but causes the vertical brass overflow tube to contact the float. Honda designed all of the cleaning ports, drain screws, and adjustment screws to face the right side of the bike, which is the upper left in the exploded view. The drain hose spigot on the float bowl faces the same way as the adjustment screws. The other way to tell is by shaking the carburetor. If you can hear the float rattling inside then the float is not stuck so the float bowl is on correctly. 

While every other moped carburetor is a sliding throttle valve type, this one is a swinging plate throttle valve. The reason is to be flatter, to get more clearance from the bottom of the frame. The manual choke is also a swinging plate, with an automatic release.

Some servicing can be done with the carburetor installed. It is easy to clean the idle passages and jet by spraying a one second long burst of carb spray into the idle mixture screw hole, followed by compressed air. The running engine is allowed to consume the flammable solvent before the next burst is sprayed in, to prevent the engine from getting flooded.

5. Keihin 

#  size 0carb   years code km  models
a  ∅12   006A ’74-75 131 00 MR50 Elsinore (US)
b  ∅10 PA06A ’73-75 122 40 PM50 Canguro, PM50 Novio
b  ∅10 PA06A ’75-78 143 40 PF50M, PF50R (BE NL NZ)
c  ∅12 PA07A ’75-78 143 50 PF50M, PF50R (FR UK CA)

1. ’73 PM50 Canguro, 2. ’74 PM50 Novio, 3. ’75-78 PF50M