Engine Idling Speed Adjustment; Valve Clearance Inspection And Adjustment - Yamaha YZ250F(V) Owner's Service Manual

VALVE CLEARANCE INSPECTION AND ADJUSTMENT

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ENGINE IDLING SPEED ADJUSTMENT/

ENGINE IDLING SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it up.
2. Adjust:
• Engine idling speed
Adjustment steps:
• Adjust the pilot screw.
Refer to "PILOT SCREW ADJUSTMENT"
section.
• Turn the throttle stop screw 1 until the
specified engine idling speed.
NOTE:
Using a digital engine tachometer for idle
speed adjustment, detect the engine idling
speed by bringing the sensing element c of
the engine tachometer close to the ignition
coil 2.
To increase idle speed → Turn the throt-
tle stop screw 1 in a.
To decrease idle speed → Turn the throt-
tle stop screw 1 out b.
Engine idling speed:
1,900 ~ 2,100 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 CHAPTER 4.
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