Yamaha TT-R50E, Owner'S Service Manual

Page: 142 / 390

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INSP
ADJ
IDLE SPEED ADJUSTMENT/
VALVE CLEARANCE ADJUSTMENT
IDLE SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it up.
2. Attach:
• Tachometer
To spark plug lead.
3. Adjust:
• Idle speed
Adjustment steps:
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
.
Engine idling speed:
1,600 ~ 1,800 r/min
1
a
b
VALVE CLEARANCE 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:
• Spark plug cap
1
• Spark plug
• Tappet cover (intake side)
2
• Tappet cover (exhaust side)
3
• Camshaft sprocket cover
4
3
4
1
2
2. Remove:
• Timing plug
1
• Crankshaft end cover
2
• O-rings
1
2