Thump TSX-C 125SW, Owner'S Manual

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62
Valve Clearance
Excessive valve clearance will cause noise and eventual engine damage.
Little or no clearance will prevent the valve from closing and cause
valve damage and power loss. Check valve clearance when the engine is
cold at the intervals specified in the Maintenance Schedule.
The checking or adjusting of the clearance should be performed while the
engine is cold. The clearance will change as engine temperature rises.
1. Remove the cylinder head cover by removing the bolts and mount
rubbers.
2. Remove the cylinder head cover gasket.
3. Remove the crankshaft hole cap and timing hole cap
4. Rotate the generator flywheel counterclockwise until the T mark on the
flywheel lines up with the index mark on the left crankcase cover. In
this position, the piston may either be on the compression or exhaust
stroke.
The adjustment must be made when the piston is at the top of the com-
pression stroke when both the intake and exhaust valves are closed.
This condition can be determined by moving the rocker arms. If they
are free, it is an indication that the valves are closed and that the piston
is on the compression stroke. If they aretight and the valves are open,
rotate the flywheel 360° and realign the T mark to the index mark.
5. Check the clearance of both valves by inserting a feeler gauge between
the adjusting screw and the valve stem.
Clearance should be:
Intake: 0.003” in
Exhaust: 0.005” in