CF MOTO CF500-5, Service Manual

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6-22
Move the automatic decompression weight with
hand and check if it is operating smoothly. If it is
not working smoothly, replace with a new camshaft/
automatic decompression assembly.
Cam Wear
Worn cams can often cause mistimed valve
operation resulting in reduced power output. The
limit of cam wear is specified for both IN and EX
cams in terms of cam height ¡°a¡±. Measure with a
micrometer the cam height. Cam height out of
range:--Replace
Camshaft Journal Wear
Check whether each journal is worn to the limit by
measuring camshaft journal oil clearance with the
camshaft installed.
Camshaft journal oil clearance
Install cylinder head cover and tighten bolts evenly
and diagonally to the specified torque:
Service limit: 0.15mm
Clean off materials from cylinder head and cover;
Install camshaft with plastic gauge;
Tightening torque: 10 N . m
Remove cylinder head cover, read the width of the
compressed plastic gauge with envelop scale. The
reading should be taken from the widest part.
Note: Do not turn the camshaft with plastic gauge
in place.
If the camshaft journal oil clearance exceeds the
limit, measure the outer diameter of camshaft;
Replace either cylinder head set or the camshaft if
the clearance is not correct.
Tool: Plastid Gauge
Automatic Decompression
Cam height service limit:
IN: 33.130mm
EX: 33.200mm
Tool: micrometer (25-50mm)