Checking The Valves And Valve Guides - Yamaha YBR125ED 2005 Service Manual

VALVES AND VALVE SPRINGS
EAS00239
CHECKING THE VALVES AND VALVE
GUIDES
The following procedure applies to all of the
valves and valve guides.
1. Measure:
2. Replace:
NOTE:
_
To ease valve guide removal and installation,
and to maintain the correct fit, heat the cylinder
head to 100 °C (212 °F) in an oven.
M
a. Remove the valve guide with the valve
b. Install the new valve guide with the valve
5 - 23
• 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>: 0.080 mm (0.0032 in)
Exhaust
0.025 ~ 0.052 mm
(0.0010 ~ 0.0020 in)
<Limit>: 0.100 mm (0.0039 in)
• valve guide
MMM M MMM M M MMM M M MMM
guide remover 1.
guide installer 2 and valve guide remover
1.
ENG
M M MMM M M MMM M MMM