Checking And Adjusting The Valve Cap - Braaap Moto3 User Manual

Checking and adjusting the valve gap
Too great a valve gap will produce noise while too narrow or no gap will make it unable to close the valve and cause the
valve ablation or even result in degradation of engine power. The valve gap must therefore be checked regularly. For State
Standard III engine, valve has been cleaned and polished so as to ensure reasonable valve gap.
Check and adjust the valve gap while engine is cold. Proceed as follows:
1. Remove the central hole cover on the left engine cover (ignition timing
observation hole).
2. Remove the valve cover or cylinder cap from the cylinder end.
Cylinder cap
3. Dock the T-wrench into the central hole of the engine cover, clip it onto the
flywheel nut and turn the flywheel clockwise until the T mark on the flywheel is
lined up with that on top of the cover. Then gently turn the rocker arm. If it is loose
(with gap), it means the piston is on the top dead center of the compression
stroke. The valve can be adjusted. If the rocker arm is tight, it means the piston
is on the bottom dead center of the exhaust stroke. In this case, continue turning
the T-wrench clockwise by 360 degrees until the line marks are aligned and then
adjust the valve. Check the valve gap by inserting a feeler gauge into the valve
adjusting screw and valve end. Standard valve gap: Refer to the Specifications.
4. If the adjustment is needed, unscrew the locknut of valve and adjust the
adjusting screw till the feeler gauge inserted into the valve is resisted slightly.
5. The exhaust is discharged from the exhaust pipe of engine crankcase, but is
charged in the air filter through exhaust gas recycling system.
6. The motor with negative pressure pipe plays a role in obstructing the air in oil
return so as to prevent the atmosphere from flowing back. After the adjustment,
screw down "locknut" to prevent looseness, check the valve gap again and put
the valve cover (or cylinder cap) and two hole caps on left case cover.
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Moto3 User Manual