Yamaha WR250FM Engine Idling Speed Adjustment, Valve Clearance Inspection and Adjustment

ENGINE IDLING SPEED ADJUSTMENT/ VALVE CLEARANCE INSPECTION AND ADJUSTMENT

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 throt- tle stop screw 1 in a.

To decrease idle speed → Turn the throt- tle stop screw 1 out b.

Inductive tachometer: YU-8036-B

Engine tachometer: 90890-03113

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.

2.Drain:

•Coolant

Refer to “COOLANT REPLACEMENT” section.

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