7-11
SETTING
TUN
Symptom
Setting
Checking
0~1/4 throttle
Use jet needle having a smaller
Number of turns-back
→
Hard breathing
diameter.
Correct properly
Speed down
Overflow from carburetor
0~1/4 throttle
Use jet needle having a larger
Poor acceleration
diameter.
White smoke
Unstable at low speeds
Lower jet needle clip position.
Pinking noise
(1 groove down)
Turn in pilot air screw.
Poor response at extremely
Reduce pilot jet calibration No.
Dragging brake
low speed
Turn out pilot air screw.
Overflow from carburetor
If not effect, reverse the above
procedures.
Poor response in the
Raise jet needle clip position.
range of low to
If no effect, reverse the above
intermediate speeds
procedures.
Poor response when
Check overall settings.
Check air cleaner for fouling.
throttle is opened quickly
Use main jet having lower
calibration No.
Raise jet needle clip position.
(1 groove up)
If no effect, reverse the above
procedures.
Poor engine operation
Turn in pilot air screw.
Check throttle valve operation.
This should be taken simply for an example.
It is necessary to set the carburetor while
checking the operating conditions of the
engine and discoloration of spark plugs.
Normally, carburetor setting is made by
means of the main jet, needle clip position,
pilot jet and pilot air screw. If the result of set-
ting is still unsatisfactory, it is advisable to
change the sizes of the jet needle.
5MW-9-30-7 7/6/00 2:18 PM Page 21
