Removing The Valves And Valve Springs - Yamaha YXR70FX Service Manual

VALVES AND VALVE SPRINGS
EBS00238
REMOVING THE VALVES AND VALVE
SPRINGS
The following procedure applies to all of the
valves and related components.
TIP:
_
Before removing the internal parts of the cylin-
der head (e.g., valves, valve springs, valve
seats), make sure the valves properly seal.
1. Check:
• valve sealing
Leakage at the valve seat → Check the
valve face, valve seat, and valve seat width.
Refer to "CHECKING THE VALVES AND
VALVE SPRINGS".
M MMM
a. Pour a clean solvent a into the intake and
exhaust ports.
b. Check that the valve seals properly.
There should be no leakage at the valve
seat 1.
L LLL
2. Remove:
• valve cotters
TIP:
_
Attach a valve spring compressor 1 and
attachment 2 between the valve spring
retainer and the cylinder head to remove the
valve cotters.
4 - 28
ENG
M MMM M M MMM M M MMM M M MMM
L LLL L L LLL L L LLL L L LLL
Valve spring compressor
90890-04019, YM-04019
Valve spring compressor attach-
ment
90890-01243
Valve spring compressor adapter
(26 mm)
YM-01253-1
M M MMM M MMM
L L LLL L LLL