Contents
carburetor years eng Honda model
1. 50A, 50B– ’66-67 ohc P25, P50
1. 50B, 50B– ’67-68 ohc P50
2. C4A, C5A ’69-70 ohc PC50
2. S4A, S5A ’69-70 ohc PS50
2. C4B, C5B ’70-73 ohv PC50K1, PS50K1
2. S4B, S5B ’70-73 ohv PS50K1
2. F4A, F5A ’72-73 ohv PF50 Amigo
1. Keihin
size carb part# frame# range model
size carb part# frame# range code eng km model
09? 50A 315 P25-A000001-00000 044 ohc 40 ’66-67 P25
09? 50A 681 P50-100001-148606 044 ohc 40 ’67-68 P50, P50 export
10? 50B 405 P50-128651-148606 044 ohc 40 ’67-68 P50 (US)
10? 50B 691 P50-128651-148606 044 ohc 40 ’67-68 P50 export
10? 50B 683 P50-148607-000000 044 ohc 40 ’68-68 P50, P50 (US)
1. 1964 P25 (NL model), 2. 1967 Honda P50, 3. 1968 P50 (US model)
4. P50 carburetor specs from the Honda service manual
Bore: 42.0 mm, stroke 35.6 mm, displacement: 49.3 cc. P50’s have down-draft carburetors, unusual.
50B carbs do not have a replaceable float valve. It’s part of, and only sold with, the float chamber cover.
50B has a larger carb size ∅10? and jet #58. 50A has a smaller carb size ∅9? and jet #55.
1. #0 16010-044-004, 2. #1 16010-044-680
A# aabb B# price a. 50A, a. 50A-610, b. 50B-NL, b. 50B
00 1000 00 N/A 16100-044-315 carburetor 50A-000 P25
00 0100 00 N/A 16100-044-681 carburetor 50A-NL P50
00 0010 70 N/A 16100-044-405 carburetor 50B-610 P50, P50 (US)
00 0001 70 N/A 16100-044-683 carburetor 50B-000 P50, P50 (US)
00 1100 00 N/A 16010-044-004 gasket set 4 12 13 15 3×20 24 27 32
12 1100 00 N/A 16173-001-004 rubber seal ring
13 1100 00 N/A 16188-044-004 valve fiber washer 7.2 x 10.5
24 1100 00 N/A 16123-044-004 jet access gasket
32 1100 00 N/A (not sold separately) choke shaft o-ring
00 0011 1 $14 16010-044-680 gasket set 4-piece 4 15 20 27
27 1111 1n 0$2 16174-044-004 float o-ring 1.5 x 40 (43od)
04 1111 1p 0$5 16171-044-004 top rubber washer 10 x 15 x 1
15 1111 1r 0$5 16175-001-004 needle jet o-ring 2 x 4 (8od)
20 3333 1i 0$2 16175-260-004 jet/screw o-ring 2 x 2.5 (6.5od)
00 0011 02 N/A 16012-044-681 needle set 2a 2b 2c 2d
06 1111 2a 0$5 16156-044-004 throttle w-clip
07 1111 2b 0$2 16157-044-004 needle e-clip 1.5 for 2.0 needle
08 1101 00 N/A 16151-044-681 jet needle
00 0011 2c N/A 16151-044-683 jet needle
16 1000 00 N/A 16133-044-004 needle jet
16 0100 00 N/A 16133-044-681 needle jet 2.6 x 1.55
00 0011 2d N/A 16133-044-683 needle jet 2.6 x 2.0
00 1111 03 N/A 16014-044-004 top set 3a 3b 1p
03 1111 3a N/A 16119-044-004 carb top M16-1.0
02 1111 3b 0$3 16118-044-004 cable adjuster male M6-0.75
11 1100 00 N/A 16125-044-004 float valve set .
00 0011 04 N/A 16015-044-014 chamber/valve set 4a 1n
00 0011 4a N/A 16112-044-014 chamber cover w/valve .
26 1100 00 N/A 16112-044-004 float chamber cover
00 1111 05 N/A 16016-044-014 screw set 5a 5b 5c 5d 1i 1i
18 1111 5a N/A 16163-044-014 idle speed screw
19 1111 5b N/A 16162-259-004 idle air screw
21 1111 5c N/A 16182-011-004 idle speed spring
22 1111 5d N/A 16181-202-004 idle air spring
00 0011 06 N/A 16022-044-680 valve (slide) set 6a 6b
09 1111 6a N/A 16141-044-683 throttle valve (slide)
05 1111 6b N/A 16185-044-004 throttle spring
28 1100 00 N/A 16122-044-004 float
00 0011 08 N/A 16122-044-014 float from #A148607
01 1111 09 N/A 16194-044-004 cable boot
30 4400 00 0$1 93600-04008 00 bowl screw M4 x 8 sunk-phil
00 0022 10 .80 93500-03008 00 bowl screw M3 x 8 phil
00 0011 11 0$1 93500-04008 00 screw M4 x 8 phil
00 0011 12 .70 94111-03000 00 bowl lock washer M3
25 1100 00 N/A 99120-05504 00 main jet 55
00 0011 13 N/A 99114-044-0581 main jet 58
17 1100 00 N/A 99144-03504 00 slow jet 35
00 0011 14 N/A 99203-044-0351 slow jet 35
Part Sets: Before 1968 most Honda parts were sold individually. That is how 50A is listed and illustrated. Starting in 1968, many Honda parts were only sold in sets. That is how 50B is listed and illustrated.
Jets: 99120-0xx14 = 99114-044-0xx1
2. Keihin
4 or 5: In this Keihin carb family the second digit of the model name is either 4 or 5. That tells the speed and power version. 4 means 40 km per hour. 5 means 50 km per hour. Each country has it’s own speed limits and safety requirements.
9 or 10 mm: “4” carbs for 40 km/h bikes are size 9 millimeter. “5” carbs for 50 km/h bikes are size 10 mm.
# carb years 0 frame # range model
# carb years 0 frame # range code km OHC model
C C4A 69-70 1000000-1057917 063 40 PC50
C C5A 69-70 1057918-1060412 063 50 PC50A (1306302)
2 C5A 69-70 1060413-1000000 063 50 PC50 Little Honda (US)
2 C5A 69-70 1000000-1001412 064 50 PS50 export
S S4A 69-70 1000000-1001412 064 40 PS50 Holland
S S5A 69-70 1001413-1000000 064 50 PS50
# carb years 0 frame # range 0code km OHV model
S S4B 70-71 C00000-C02583 082 40 PS50K1
S S5B 70-71 C00000-C02583 082 50 PS50K1
C C4B 70-73 2000000-2039616 081 40 PC50K1
C C5B 71-73 2039617-2000000 081 50 PC50K1
8 C5B 71-73 C02584-C00000 082 50 PS50K1
F F4A 72-73 PF50E-C00001- 099 40 PF50 Amigo
F F5A 72-73 PF50E-C00001- 099 50 PF50 Amigo
ohc engine 1. ’68 PC50A, 2. ’69 PC50 (US), 3. ’70 PS50
ohv engine 1. ’70 PS50K1, 2. ’73 PC50K1, 3. ’73 PF50
1969-70 PC50: Before April 1970, the PC50 had a OHC engine (over head cam). The valves were operated by a cam in the head, driven by a cam chain.
Spigot mount: The Keihin C4A, C5A, S4A, S5A, C4B, C5B, S4B, S5B carburetors were spigot mount type. They had a round float bowl gasket (with three flat sides when installed), a push-in jet, jet pad, completely round “donut” float, all metal float needle with replaceable float seat.
1970-73 PC50K1: After April 1970, the PC50K1 had a OHV engine (over head valve). The valves were operated by pushrods from a cam down in the case.
Flange mount: The Keihin F4A, F5A, carburetors for the 1970-73 PF50 were flange mount type with 32mm bolt spacing. There was a diamond shaped gasket rather than an o-ring like all later flange mount carbs. Everything else was the same, round float bowl gasket (with three flat sides when installed), a push-in jet, jet pad, completely round “donut” float, all metal float needle with replaceable float seat.
1. Keihin C5A carburetor, 2. Keihin F4A
3. Zenith 11-HL on 1970’s Spanish Honda PS50
4. Keihin C4A C5A S4A S5A specs from PC50 service manual
1. 16010-063-000, 2. 16010-063-004, 3. 16010-114-305
c# CSSCF price Honda part# carb for models
00 10000 N/A 16100-063-690 C4A 69-70 PC50
00 10000 N/A 16100-063-004 C5A 69-70 PC50, PS50 to-1001412
00 01000 N/A 16100-064-000 S4A 69-70 PS50 Holland
00 01000 N/A 16100-064-014 S5A 69-70 PS50 1001413-on
00 00100 N/A 16100-082-691 S4B 70-71 PS50K1 to-C02583
00 00100 N/A 16100-082-004 S4B 70-71 PS50K1 Holland
00 00100 N/A 16100-082-001 S4B 70-71 PS50K1 to-C02583
00 00100 N/A 16100-082-014 S5B 71-73 PS50K1 C02584-on
00 00010 N/A 16100-081-690 C4B 70-73 PC50K1 to-2039616
00 00010 N/A 16100-081-014 C5B 71-73 PC50K1 2039617-on
00 00001 N/A 16100-099-690 F4A 72-73 PF50
00 00001 N/A 16100-099-600 F5A 72-73 PF50
c# CSSCF price Honda part# parts list
01 11000 N/A 16010-063-004 gasket solo-set 1d 1e 1n 1p 1y
01 00111 $34 16010-063-000 gasket solo-set 1d 1e 1n 1p oo 1r
01 00111 $34 16010-114-305 gasket multi-set 1d 1e 1n 1p 1q 1r
1d 11111 0$2 16176-551-004 main jet o-ring 1 x 3 (5 od)
1e 11111 $14 16197-063-004 jet pad disk Ø7.5 x 1.7
1n 11111 0$3 16173-063-004 float bowl o-ring 1.5 x 40 (43 od)
1p 11111 0$5 16171-044-004 top rubber washer 10 x 15 x 1
1q 00000 0$2 00000-000-000 tiny seal washer 3 x 6 x 0.5
1r 00111 0$5 16175-001-004 drain screw o-ring 2 x 4 (8od)
1y 11000 N/A 16189-056-004 drain screw seal washer 6 x 8 x 0.5
02 11010 N/A 16012-064-004 needle set 2a 2c 2d 2f
2a 11010 N/A 16151-063-004 jet needle
2b 00101 N/A 16151-063-690 jet needle
2c 11111 0$5 16156-044-004 needle w-clip
2d 11111 0$2 16157-044-004 needle e-clip 1.5 for 2.0 needle
2e 10000 N/A 16133-063-004 needle jet 2.1 x 2.5
2f 01110 N/A 16133-081-004 needle jet
2g 00001 N/A 16133-081-690 needle jet
03 11111 N/A 16013-064-004 float set 3a 3b 3c 3d 3e 10
3a 11111 $13 16123-063-004 float needle (all metal)
3b 11111 N/A 16122-063-004 float
3c 11111 N/A 16127-063-014 float arm
3d 11111 N/A 16126-063-014 float hinge pin
3e 11111 N/A 16196-063-014 float pin plate
04 11111 N/A 16014-064-004 top set 4a 4b 1p
4a 11111 N/A 16119-063-004 top with pipe
4b 11111 N/A 16118-045-004 cable adjuster female M6-0.75
05 11000 N/A 16015-064-004 chamber set 5a 5c 1n 1q
05 00100 N/A 16167-082-004 chamber set
05 00111 N/A 16167-082-014 chamber set 5b 5d 1n 1r
5a 11000 N/A (not sold separately) chamber bare
5b 00111 N/A (not sold separately) chamber bare
5c 11000 N/A 16164-225-004 drain screw A
5d 00111 N/A 16162-304-004 drain screw B
06 11111 N/A 16016-063-004 adjustment screw set
6a 11111 N/A 16163-063-014 idle speed screw
6b 11111 N/A 16162-044-004 idle air screw
6b 11111 N/A 16181-001-004 idle air spring
6c 11111 N/A 16181-250-004 idle speed spring
07 11111 N/A 16022-063-004 throttle valve set
7a 11111 N/A 16141-063-004 throttle valve (slide)
7b 11111 N/A 16185-044-004 throttle spring
09 11000 N/A 16194-063-004 cable pipe cover
09 00111 N/A 16194-063-014 cable pipe cover
10 11111 0$2 93500-0300500A float screw M3 x 5 phil
11 22222 0$1 93500-040120A bowl screw M4 x 12 phil
12 11111 .50 94111-030000 spring washer M3
13 22222 .50 94111-04000 spring washer M4
15 11111 N/A 99201-063-0550 main jet #55 push-in
15 11111 N/A 99201-063-0620 main jet #62 push-in
18 11111 N/A (not sold separately) idle jet press-in tube 0.35=0.0138″
1. Keyster 0605 kit for PC50A has no #1e
for C4A except no 1e, C5A except 15 1e
for C4B except 2f 1e, C5B except 2f 15 1e
for F4A except 2g 1e, F5A except 2f 15 1e
2. #5c #5d drain plugs