7 - 4
T U N
SETTING
Main jet adjustment
The richness of the air-fuel mixture at full throt-
tle can be set by changing the main jet
1
.
If the air-fuel mixture is too rich or too lean, the
engine power will drop, resulting in poor accel-
eration.
Effects of changing the main jet (reference)
Å
Idle
ı
Fully open
Standard main jet
#165
1/4
1/2
3/4
+10%
#165
–10%
A
B
#175
#155
Pilot screw adjustment
The richness of the air-fuel mixture with the
throttle fully closed to 1/8 open can be set by
turning the pilot screw
1
. Turning in the pilot
screw will make the mixture lean at low
speeds, and turning it out will enrich it.
* Except for USA
NOTE:
The pilot screw is set at the factory, there is no
need to adjust it.
If the idling speed fluctuates, turn the pilot
screw only 1/2 of a turn in either direction.
Effects of adjusting the pilot screw (refer-
ence)
Å
Idle
ı
Fully open
1
2-1/8 turns out
2
1-1/8 turns out
3
1-5/8 turns out
Standard pilot
screw position
1-5/8 turns out
* 1-1/2 turns out
(for reference only)
1/4
1/2
3/4
+5%
–5%
A
B
1
2
3