Yamaha Scorpio Service Manual page 105

VALVES AND VALVE SPRINGS
4.Install:
Valve cotters 1
G
NOTE:
Install the valve cotters while compressing the
valve spring with a valve spring compressor
2.
5.Secure the valve cotters onto the valve stem
by tapping lightly with a piece of wood.
CAUTION:
Do not hit so much as to damage the valve.
4 - 28
ENG
Valve spring compressor:
90890-04019