IDENTIFY THAT JET
First identify the carb manufacturer, mikuni, keihin, hitachi, holley.
Second the jets need to be located. The jets are under the float bowl cover. The float bowl cover is held in place by 4 screws - on most carburetors.

Remove the float bowl cover screws.




The jets are normally a brass color, they are circled in the above photo. Some of the jets are located elsewhere in the carb, but the ones circled are most often replaced.

The long piece below is not the main jet:
jet


Unscrew and the main jet is on the left:
jet

Look on the jets for a number (which is the size of the jet) and the manufacturer ID stamp.


GENUINE MIKUNI jets will have a stamping on them which is a "square within a square" on them:

GENUINE KEIHIN jets will have a "K star" stamping on them:

 

Jets are listed below
KEIHIN
MIKUNI
HITACHI
TEIKEI

Below are the different types of jets, look for one that is similar to the jet and then check measurements to verify it is your jet. Many of the jets are similar so be sure to check entire list.

KEIHIN

n1001-806 keihin jet
OVERALL LENGTH = 9mm
HEAD DIAMETER = 8mm
THREAD DIAMETER = 9.9mm
KEIHIN 1001-806

99101-124 and 99101-ZF5
OVERALL LENGTH = 8.5 mm
SHAFT DIAMETER = 5.5 mm
DIAMETER OF THREAD = 6.9 mm
KEIHIN 99101-124 and 99101-ZF5

 


OVERALL LENGTH = 8.5 mm
SHAFT DIAMETER = 4.8 mm
DIAMETER OF THREAD = 5.9 mm
KEIHIN 3C

 

 

n424-52 keihin leak jet
OVERALL LENGTH = 8.5mm
DIAMETER OF THREAD = 3.5mm
KEIHIN Leak jet N424-52

 

 


OVERALL LENGTH = 16.5mm
THREAD DIAMETER = 4.9mm
KEIHIN 99101-357

 

 

n424-14 keihin jet
OVERALL LENGTH = 22mm
THREAD DIAMETER = 4.9mm
N424-14

 

 

n424-27 keihin jet
OVERALL LENGTH = 8mm
HEAD DIAMETER = 7mm
THREAD DIAMETER = 5.9mm
KEIHIN N424-27

 

 

main jet 99101-393
OVERALL LENGTH = 8mm
HEAD DIAMETER = 6mm
THREAD DIAMETER = 4.9
KEIHIN 99101-393

 

 

KEIHIN N424-36 NICKEL PLATED
OVERALL LENGTH = 8mm
HEAD DIAMETER = 6mm
THREAD DIAMETER = 4.9mm
KEIHIN N424-36 NICKEL PLATED

 

 

KEIHIN 99101-116
OVERALL LENGTH = 7mm
HEAD DIAMETER = 5mm
THREAD MAJOR DIAMETER = 3.9mm
KEIHIN 99101-116

 

KEIHIN N424-35 NICKEL PLATED
OVERALL LENGTH = 7mm
HEAD DIAMETER = 5mm
THREAD DIAMETER = 3.9mm
KEIHIN N424-35 NICKEL PLATED

 


OVERALL LENGTH = 6.5 mm
HEAD DIAMETER = 4.3 mm
THREAD DIAMETER = 3.4 mm
KEIHIN 1001-108

 

 

99201-601 keihin jet
OVERALL LENGTH = 9.4mm
DIAMETER = 4.95mm
KEIHIN 99201-601

 

 

99202-601 keihin jet
OVERALL LENGTH = 9.6mm
DIAMETER = 6.0mm
KEIHIN 99202-601

 


OVERALL LENGTH = 28mm
DIAMETER OF THICKEST PART = 5mm
TIP DIAMETER =3mm
KEIHIN 3L

 

KEIHIN N424-21
OVERALL LENGTH = 28mm
THREAD DIAMETER = 5.9mm
KEIHIN N424-21

jet keihin n424-26
OVERALL LENGTH = 23.5mm
THREAD DIAMETER = 5.9mm
KEIHIN N424-26

 

KEIHIN N424-74C
OVERALL LENGTH = 28mm
HEAD DIAMETER = 5mm
THREAD DIAMETER = 4.9mm
KEIHIN N424-74C

 

keihin 3J
OVERALL LENGTH = 28mm
DIAMETER OF THICKEST PART = 5mm
THREAD DIAMETER = 4.9mm
KEIHIN 3J

 

 

KEIHIN N424-22
OVERALL LENGTH = 28mm
DIAMETER OF HEAD = 5.5mm
THREAD DIAMETER = 4.4mm
KEIHIN N424-22

 

N424-32
OVERALL LENGTH = 21mm
DIAMETER = 5mm
N424-32

 

KEIHIN N424-24
OVERALL LENGTH = 32mm
THREAD DIAMETER = 3.4mm
HEAD DIAMETER = 5.5mm
TIP DIAMETER = 2.0mm
KEIHIN N424-24

 

KEIHIN 99124-076
OVERALL LENGTH = 28mm
DIAMETER OF HEAD = 5.5mm
THREAD DIAMETER = 3.4mm
TIP DIAMETER = 2.0mm
KEIHIN 99124-076

 

KEIHIN N424-25B
OVERALL LENGTH = 15mm
THREAD DIAMETER = 4.5mm
KEIHIN N424-25B

 

 

KEIHIN N424-330
OVERALL LENGTH = 13mm
HEAD DIAMETER = 4.5mm
THREAD DIAMETER = 4.4mm
KEIHIN N424-330 and N424-33

 

 

 

 

 

MIKUNI

 

 

MIKUNI 4/042
OVERALL LENGTH = 11.5mm
THREAD DIAMETER = 5.2mm
THREAD PITCH = 5.25 x 0.9
MIKUNI 4/042

 

 

MIKUNI M10-14
OVERALL LENGTH = 8mm
DISTANCE ACROSS FLATS = 6mm
MIKUNI M10-14

 

 

MIKUNI VM11-22
OVERALL LENGTH = 10.6mm
HEAD DIAMETER = 8mm
THREAD DIAMETER = 5.9mm
THREAD PITCH = 6.0 x 0.8mm
MIKUNI VM11-22

 

MIKUNI N100.604
OVERALL LENGTH = 9mm
HEAD DIAMETER = 8mm
THREAD DIAMETER = 4.9mm
THREAD PITCH = 5.0 x 0.7
MIKUNI N100.604

 

 

N102.221
OVERALL LENGTH = 9mm
HEAD DIAMETER = 6mm
THREAD DIAMETER = 4.9mm
THREAD PITCH = 5.0 x 0.7
MIKUNI N102.221

 

 

MIKUNI N100.606
OVERALL LENGTH = 6.5 mm
THREAD DIAMETER = 3.9 mm
LARGEST DIAMETER = 4 mm
MIKUNI N100.606

 

 


OVERALL LENGTH = 9mm
HEAD DIAMETER = 6mm
THREAD DIAMETER = 5.9mm
B42/55

 


MIKUNI N208.099
OVERALL LENGTH = 9 mm
LARGEST DIAMETER = 6 mm
REQUIRES O-RING 616-12001
MIKUNI N208.099

 

 

vm17/1002
OVERALL LENGTH = 6.0 mm
THREAD DIAMETER = 4.0 mm
MIKUNI VM17/1002

 

MIKUNI M28/1001
OVERALL LENGTH = 9.5 mm
THREAD DIAMETER = 3.9 mm
MIKUNI M28/1001

 

MIKUNI BS30-97
OVERALL LENGTH = 7.5mm
THREAD DIAMETER = 3.9mm
MIKUNI BS30-97

 

 

MIKUNI N101.043
OVERALL LENGTH = 16.0 mm
THREAD DIAMETER = 5.9 mm
LARGEST DIAMETER = 6.5 mm
MIKUNI N101.043

 

 

MIKUNI BS30/96
OVERALL LENGTH = 14 mm
THREAD DIAMETER = 4.9 mm
6 holes in shaft
MIKUNI BS30/96

 

 

MIKUNI N151.067
OVERALL LENGTH = 14 mm
THREAD DIAMETER = 4.9 mm
MIKUNI N151.067

 

MIKUNI VM22/210
OVERALL LENGTH = 14 mm
THREAD DIAMETER = 4.9 mm
8 holes in shaft
MIKUNI VM22/210

 

 

MIKUNI N224.103
OVERALL LENGTH = 28mm
HEAD DIAMETER = 5.0mm
THREAD DIAMETER = 3.9mm
THREAD PITCH = 4.0 x 0.7
TIP DIAMETER = 2.5mm
MIKUNI N224.103

 

MIKUNI VM28/486
OVERALL LENGTH = 28.0 mm
HEAD DIAMETER = 5.0 mm
THREAD DIAMETER = 3.9mm
THREAD PITCH = 4.0 x 0.7
TIP DIAMETER = 2.0 mm
MIKUNI VM28/486

 


OVERALL LENGTH = 28mm
HEAD DIAMETER = 5.0 mm
THREAD DIAMETER = 3.9mm
THREAD PITCH = 4.0 x 0.7
TIP DIAMETER = 2.0mm
MIKUNI VM28-213

 

HITACHI

hitachi main slow pilot jet
OVERALL LENGTH = 8.0 mm
HEAD DIAMETER = 7.5 mm
Hitachi main
Hitachi pilot

 

TEIKEI


OVERALL LENGTH = 8.0 mm
DISTANCE ACROSS FLATS= 7.0 mm
DIAMETER OF THREAD = 4.9 mm
TEIKEI MAIN JET


OVERALL LENGTH = 18.1 mm
DIAMETER OF HEAD= 5.0 mm
DIAMETER OF THREAD = 3.9 mm
TEIKEI SLOW JET