Yamaha WR250F(N), Owner'S Service Manual

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INSP
ADJ
ENGINE IDLING SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it
up.
2. Attach:
●
Inductive tachometer
To spark plug lead.
3. Adjust:
●
Engine idling speed
Adjustment steps:
●
Adjust the pilot screw.
Refer to “PILOT SCREW ADJUSTMENT”
section.
●
Turn the throttle stop screw 1 until the
engine runs at the lowest possible speed.
To increase idle speed
→
Turn the throttle stop screw 1 in
a
.
To decrease idle speed
→
Turn the throttle stop screw 1 out
b
.
Inductive tachometer:
YU-08036-B
Engine tachometer:
90890-03113
Engine idling speed:
1,700 ~ 1,900 r/min
VALVE CLEARANCE INSPECTION AND
ADJUSTMENT
NOTE:
●
The valve clearance should be adjusted
when the engine is cool to the touch.
●
The piston must be at Top Dead Center
(T.D.C.) on compression stroke to check or
adjust the valve clearance.
1. Remove:
●
Seat
●
Fuel tank
Refer to “SEAT, FUEL TANK AND
SIDE COVERS” section in the CHAP-
TER 4.
2. Drain:
●
Coolant
Refer to “COOLANT REPLACEMENT”
section.
ENGINE IDLING SPEED ADJUSTMENT/
VALVE CLEARANCE INSPECTION AND ADJUSTMENT