Yamaha TW200 Service Manual page 100

INSPECTION AND REPAIR
I
ENG
I' ..
I
VALVE AND VALVE GUIDE
NOTE: _
Always replace valve guide and oil seal if valve
is removed.
1. Measure:
-Stem-to-guide clearance
Stem-to-guide clearance
=
Valve guide inside diameter
® -
Valve stem diameter
@
Out of
specification~Replace
valve guide.
Stem-to-guide Clearance:
Intake 0.010-0.037 mm (0.0004-0.0015 in)
Exhaust 0.025-0.052 mm (0.001-0.002 in)
CD
Bore gauge
Valve guide replacement steps:
NOTE: _
Heat
th~
cylinder head in an oven to 10QoC
(212°F) to ease guide removal and installation
and to maintain correct interference fit.
- Remove the valve guide using the Valve Guide
Remover
(1).
Valve Guide Reamer:
PIN YM-04066
Valve Guide Installer:
PIN
YM-04065-A
Valve Guide Remover:
PIN YM-04064-A
- After installing the valve guide, bore the valve
guide using th.e Valve Guide Reamer
@
to
obtain proper stem-to-guide clearance.
-Install the valve guide (New) using the Valve
Guide Installer
~
and Valve Guide Remover
(1).
4-20