Yamaha YZ450F(S), Owner'S Service Manual

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ENG
VALVES AND VALVE SPRINGS
REMOVAL POINTS
Valve lifter and valve cotter
1. Remove:
●
Valve lifters 1
●
Pads 2
NOTE:
Identify each lifter 1 and pad 2 position very
carefully so that they can be reinstalled in their
original place.
2. Check:
●
Valve sealing
Leakage at the valve seat
→
Inspect
the valve face, valve seat and valve
seat width.
Checking steps:
●
Pour a clean solvent 1 into the intake and
exhaust ports.
●
Check that the valve seals properly.
There should be no leakage at the valve
seat
2 .
3. Remove:
●
Valve cotters
NOTE:
Attach a valve spring compressor 1 between
the valve spring retainer and the cylinder head
to remove the valve cotters.
Valve spring compressor:
YM-4019/90890-04019