Yamaha TT-R125(R) Owner's Service Manual page 258

VALVES AND VALVE SPRINGS
REMOVAL POINTS
Valve
1. Check:
Checking steps:
G
G
2. Remove:
NOTE:
Attach a valve spring compressor 2 between
the valve spring retainer and the cylinder head
to remove the valve cotters.
3. Remove:
NOTE:
Identify the position of each part very carefully
so that it can be reinstalled in its original place.
4 - 25
Valve sealing
G
Leakage at the valve seat → Inspect
the valve face, valve seat and valve
seat width.
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.
Valve cotters 1
G
Valve spring compressor:
YM-4019/90890-04019
Valve spring retainer 1
G
Valve spring 2
G
Valve 3
G
Valve stem seal 4
G
Valve spring seat 5
G
ENG