Valves And Valve Springs - Yamaha TT-R90 Handbuch

VALVES AND VALVE SPRINGS

REMOVAL POINTS
Valve removal
1. Remove:
NOTE:
Attach a valve spring compressor 2 between
the valve spring retainer and the cylinder head
to remove the valve cotters.
INSPECTION
Valve
1. Measure:
2. Measure:
4 - 17
Valve cotters 1
G
Valve spring compressor:
YM-4019/90890-04019
Stem-to-guide clearance
G
Stem-to-guide clearance =
valve guide inside diameter a –
valve stem diameter b
Out of specification → Replace the
valve guide.
Clearance (stem to guide):
Intake:
0.010 ~ 0.037 mm
(0.0004 ~ 0.0015 in)
<Limit>: 0.08 mm (0.003 in)
Exhaust:
0.025 ~ 0.052 mm
(0.0010 ~ 0.0020 in)
<Limit>: 0.10 mm (0.004 in)
Runout (valve stem)
G
Out of specification → Replace.
Runout limit:
0.02 mm (0.0008 in)
ENG