Idle Speed Adjustment - Yamaha Big Bear YFM400R Owner's Manual

EBU01302

Idle speed adjustment

NOTE:
_
A diagnostic tachometer must be used for this
procedure.
_
1. Start the engine and warm it up for a few
minutes at approximately 1,000 to
2,000 r/min. Occasionally rev the engine
to 4,000 to 5,000 r/min. The engine is
warm when it quickly responds to the
throttle.
2. Connect the tachometer to the spark plug
lead, and then set the idle to the specified
idling speed by adjusting the throttle stop
screw. Turn the screw in direction a to
increase the engine speed, and in direc-
tion b to decrease the engine speed.
Specified idle speed:
1,450–1,550 r/min
1. Throttle stop screw
8-19