Checking The Camshaft; Checking The Rocker Arms And Camshaft - Yamaha YFM4FAR Service Manual

CAMSHAFT, ROCKER ARMS AND VALVES
2.Remove:
Valve cotters
G
NOTE:
Attach a valve spring compressor 1 between
the valve spring retainer and the cylinder head
to remove the valve cotters.
Valve spring compressor:
P/N. YM-04019, 90890-04019

CHECKING THE CAMSHAFT

1.Check:
Cam lobes
G
Pitting/scratches/blue discoloration →
Replace.
2.Measure:
Cam lobes length a and b.
G
Out of specification → Replace.
Camshaft lobe limit:
Intake:
a 40.52 mm (1.595 in)
b 32.08 mm (1.263 in)
Exhaust:
a 40.52 mm (1.595 in)
b 32.08 mm (1.263 in)
CHECKING THE ROCKER ARMS AND
CAMSHAFT
1.Check:
Camshaft lobe contact surface 1
G
Valve adjusters 2
G
Blue discoloration/pitting/scratches →
Replace.
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ENG