![background image](/i/yamaha/160250/yamaha-wr250fr-2002/h/yamaha-wr250fr-2002-324.png)
7 - 4
T U N
SETTING
1
Jet needle
2
Pilot air jet
3
Needle jet
4
Main jet
5
Pilot jet
6
Pilot screw
Main jet adjustment
The richness of the air-fuel mixture at full throt-
tle can be set by changing the main jet
1
.
* Except for USA
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)
È
Idle
É
Fully open
Standard main jet
#185
* #172
1/4
1/2
3/4
+10%
#185
–10%
#195
#175
È
É