Yamaha YZ450F(T) Owner's Service Manual page 308

VALVES AND VALVE SPRINGS
REMOVAL POINTS
Valve lifter and valve cotter
1. Remove:
NOTE:
Identify each lifter 1 and pad 2 position very
carefully so that they can be reinstalled in their
original place.
2. Check:
Checking steps:
• Pour a clean solvent 1 into the intake and
• Check that the valve seals properly.
3. Remove:
NOTE:
Attach a valve spring compressor 1 between
the valve spring retainer and the cylinder head
to remove the valve cotters.
4 - 34
• Valve lifters 1
• Pads 2
• Valve sealing
Leakage at the valve seat → Inspect the
valve face, valve seat and valve seat
width.
exhaust ports.
There should be no leakage at the valve
seat 2.
• Valve cotters
Valve spring compressor:
YM-4019/90890-04019
ENG