LONCIN YF300 - Page 11

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buildup and dirt by steel wire or spark plug washer.
Screw up spark plug by hand first and then by sleeve
when it is assembling, and then screw up cap of spark
plug.
Valve clearance
Caution：Engine should be under cold condition
when valve clearance is in adjustment.
Remove cylinder head cover, view-hole cap
and its decorative cover A.
Correctly aline the timing mark.
Turn crankshaft anticlockwise, aline timing mark
(T shaped line) on rotor and groove on view-hole
cap through viewing by view-hole on left front
crankcase cover, and at this moment, the piston
is at upper stopping point of compression stroke.
Timing scale line “—”on camshaft should be parallel
with joint surface on cylinder head.(Note: Air intake cam
corresponds scale line of “IN” while air exhaust cam of
“EX”.
Checking of valve clearance
Insert feeler gauge between camshaft and tappet rod for checking valve
Clearance.
Clearance of air intake valve：0.1～0.19
Clearance of air exhaust valve：0.15～0.24
Adjustment is needed when clearance is incorrect.
Adjustment of valve clearance
Remove bracket of camshaft, and then camshaft A,
tappet rod B, and finally remove adjustment washer
C; Select a new adjustment washer according to
valve clearance.
When installing adjustment washer, the side with mark
face to tappet rod of valve; and then install tappet rod
and camshaft, ensure position of timing; Measure valve
clearance after adjusted; In case re-adjustment is needed,
repeat adjustment according to steps above until it is correct;