Slow System - Suzuki RM-Z250 Owner's Service Manual

4-3 MACHINE TUNING
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.
TUNING PARTS
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 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
SIZE
mixture
Lean #35
#40
#42
#45
#48
#50
#52
#55
#58
Rich #60
P/NO.
09492-35019
09492-40022
09492-42019
09492-45032
09492-48013
09492-50023
09492-52011
09492-55017
09492-58001
09492-60016
THROTTLE VALVE OPENING
1/4 1/2 3/4