Yamaha YZ250 Owner's Service Manual page 166

IDLE SPEED ADJUSTMENT/MUFFLER INSPECTION/
SILENCER FIBER REPLACEMENT
EC35M001
IDLE SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it up.
2. Adjust:
Adjustment steps:
Turn the throttle stop screw 1 until the
engine runs at the lowest possible speed.
To increase idle speed ¡ Turn the throttle
To decrease idle speed ¡ Turn the throttle
EC35P030
MUFFLER INSPECTION
1. Inspect:
NOTE:
Install the O-rings with their depressed a facing
outward.
EC35R051
SILENCER FIBER REPLACEMENT
1. Remove:
3-15
9 Idle speed
9 O-ring 1
Damage ¡ Replace.
9 Side cover (right)
9 Bolt (silencer) 1
9 Silencer 2
9 Bolt (fiber) 3
INSP
ADJ
stop screw 1 1 in.
stop screw 1 1
out.