CB100 Carburettor

  • Carburation 22mm Keihin
  • air filter fitting is 38mm
  • Carburation Main Jet 100
  • Pilot Screw Setting 2.5 turns
Fitted as standard and confirmed on bike is a:

Keihin PD 91A RL

22mm venturi - but head side dia is 26mm

  • main jet #100
  • Air Jet #38
  • needle no #33a 2nd clip from top
  • valve slider #74b
  • pilot screw 2.5 turns (for cb125n it is 1.5 turns)
  • float height 12.5mm
I have also got these

A tl125 carb

An sl100 carb that is badly corroded

Another unkown carb similar to the cb100n stock

TL125

TL125 - this is the best condition carb

  • KG7 660a marked on top of flange
  • venturi oval = 20.0 wide x 23.2 high (area = 364.425 mm2)
  • slider = 166A 2.5
  • main jet = #98
  • slow jet = #38 - same as cb100n
  • needle = 27 3001 3rd clip from top
  • float height 21.5mm
SL100

SL100 carb

  • JA SL10a marked on top of flange
  • venturi size oval = 20.0 wide x 23.2 high (area = 364.425 mm2)
  • slider = 166 2.5
  • main jet = #110
  • slow jet = #38 - same as cb100n
  • needle = 27 202 3rd clip from top
  • float height 24mm (yep)
other carb

other carb (perhaps from cb125s or cg125 )

  • PD 88E PA marked on side of float chamber rim
  • venturi oval = 21 wide x 25.3 high
  • slider = 06B
  • main jet = #
  • slow jet = #
  • needle = EI352H
  • float height
notes

from: http://www.vintagebikeforum.org/index.php?topic=2042.0 All models are equipped with Keihin sliding valve units. Float level should be 24mm (15/16 inch) for all models except TL models which should be 21.5mm (27/32 inch). On all models, float level is checked by placing carburetor on side and allowing tang to just contact needle of fuel valve. Level is adjusted by bending tang.

Initial pilot air screw setting is 7/8 turns open for carburetor on TL models. 1 1/4 turns open for carburetors stamped “GB10A” 1 1/2 to 1 5/8 turns open on all other carburetors.

Standard main jet is:

 1. 92 on carburetors stamped "662A"
 2. 95 on all TL models
 3. 98 on carburetors stamped "660A"
 4. 100 on carburetors stamped "648A" or "667A"
 5. 105 on carburetors stamped "658A, 659A, 671A or GB10A"
 6. 110 on model XL125 and carburetors stamped "SL10A"

Standard slow jet is:

 1. 42 on model XL125
 2. 38 on all other models. 

Jet needle clip should be in: second groove from top on model XL125 and carburetors stamped “671A”. third groove from top on all other models.

info at: http://www.salocal.com/sohc/tech/carb/asmpg_mgs/jetgraph.htm too