Checking The Valves And Valve Guides - Yamaha XV16AL Service Manual

VALVES AND VALVE SPRINGS
NOTE:
Identify the position of each part very care-
fully so that it can be reinstalled in its origi-
nal place.
EAS00239
CHECKING THE VALVES AND VALVE
GUIDES
The following procedure applies to all of
the valves and valve guides.
1. Measure:
• valve stem-to-valve guide clearance
Valve stem-to-valve guide clearance =
Valve guide inside diameter a –
Valve stem diameter b
Out of specification → Replace the valve
guide.
2. Replace:
• valve guide
NOTE:
To ease valve guide removal and installa-
tion, and to maintain the correct fit, heat the
cylinder head to 100 ˚C (212 ˚F) in an oven.
5 - 46
ENG
Valve stem-to-valve guide clear-
ance
Intake
0.010 ~ 0.037 mm
(0.0004 ~ 0.0015 in)
<Limit>: 0.08 mm (0.0031 in)
Exhaust
0.025 ~ 0.052 mm
(0.0006 ~ 0.0020 in)
<Limit>: 0.1 mm (0.004 in)
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