Checking The Valves And Valve Guides - Yamaha XT660R Service Manual

VALVES AND VALVE SPRINGS
3. Remove:
NOTE:
_
Identify the position of each part very carefully
so that it can be reinstalled in its original place.
EAS00239
CHECKING THE VALVES AND VALVE
GUIDES
The following procedure applies to all of the
valves and valve guides.
1. Measure:
5 - 25
• valve spring retainer 1
• valve spring 2
• valve stem seal 3
• valve spring seat 4
• valve 5
• 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.
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
(0.0010 ~ 0.0020 in)
<Limit>: 0.10 mm (0.0039 in)
ENG