Effects of the setting parts on the throttle
valve opening
Setting part
Pilot jet
Pilot air screw
Diameter of
straight por-
5PA70040
tion
Clip position
Main jet
1 Throttle valve opening
2 Full-open
3 Full-closed
Main jet adjustment
The richness of air-fuel mixture with 3/4 ~ 4/4
throttle can be set by changing the main jet 1.
Standard main jet
1. Spark plug is too hot.
Select a main jet having higher calibrating
No. than standard. (To be enriched)
5PA70050
2. Spark plug is wet.
Select a main jet having lower calibrating
No. than standard. (To be leaned out)
Pilot air screw adjustment
The richness of the air-fuel mixture with the
throttle fully closed to 1/4 open can be set by
turning the pilot air screw 1.
Turning in the pilot air screw will make the mix-
ture enrich at low speeds, and turning it out will
lean it.
Standard pilot air
screw position
5PA70060
7 - 3
T U N
SETTING
Throttle valve opening
Full-closed1/4
1/2
2 turns out
(example)
3/4 Full-open
#138