Yamaha TT-R125Y 2009 Manuel D'atelier page 296

VALVES AND VALVE SPRINGS
4-31
3. Install:
• Valve cotters 1
TIP
While compressing the valve spring with a valve
spring compressor 2, install the valve cotters.
Valve spring compressor:
YM-4019/90890-04019
4. To secure the valve cotters onto the valve
stem, lightly tap the valve tip with a piece of
wood.
NOTICE
Hitting the valve tip with excessive force
could damage the valve.
ENG