MACHINE TUNING 4-3
As shown below, each of the asterisk (*) marked parts is located between the air/fuel passage and has its
own air/fuel mixture adjustable range in terms of the throttle valve opening. The chart indicates that the car-
buretor can supply correct air/fuel mixture to the engine in any range because of the overlapping adjustable
range of the each part.
1 SLOW SYSTEM
2 INTERMEDIATE SYSTEM
3 MAIN SYSTEM
When performing carburetor tuning, first find out in what throttle opening range an improper air/fuel mixture
is supplied, by checking the color of exhaust smoke, spark plug, throttle response, power, etc. Second,
replace or adjust the part(s) related to the throttle opening range by referring to the following instructions.
The sizes referred to in the illustrations are those of standard setting.
SLOW SYSTEM
SLOW JET (S.J.)
The slow jet meters the fuel supplied to the slow system. Each
jet size is indicated by a number. Larger number means a larger
bore diameter and fitting a larger numbered slow jet enriches the
air/fuel mixture.
Air/fuel
mixture
SIZE P/NO.
Lean #35 09492-35019
#40 09492-40022
#42 09492-42019
#45 09492-45032
#48 09492-48013
#50 09492-50023
#52 09492-52011
#55 09492-55017
#58 09492-58001
Rich #60 09492-60016
TUNING PARTS THROTTLE VALVE OPENING
MAIN JET (M.J.)
JET NEEDLE (J.N.) CLIP POSITION
JET NEEDLE (J.N.) O.D.
SLOW JET (S.J.) AND PILOT SCREW
THROTTLE OPENING
1/4 1/2
3/4
To Next Page
Loading...
