Valves And Valve Springs; Removing The Valves - Yamaha YZF-R1S Service Manual

VALVES AND VALVE SPRINGS

EAS00237

REMOVING THE VALVES

The following procedure applies to all of the
valves and related components.
NOTE:
Before removing the internal parts of the cylin-
der head (e.g., valves, valve springs, valve
seats), make sure the valves properly seal.
1. Remove:
S valve lifter 1
S valve pad 2
NOTE:
Make a note of the position of each valve lifter
and valve pad so that they can be reinstalled in
their original place.
2. Check:
S valve sealing
Leakage at the valve seat ! Check the valve
face, valve seat, and valve seat width.
Refer to "CHECKING THE VALVE SEATS".
a. Pour a clean solvent a into the intake and
exhaust ports.
b. Check that the valves properly seal.
NOTE:
There should be no leakage at the valve seat 1 .
3. Remove:
S valve cotters 1
NOTE:
Remove the valve cotters by compressing the
valve spring with the valve spring compressor
2 and the valve spring compressor attachment
3 .
5-27
ENG
Valve spring compressor
90890-04019, YM-04019
Valve spring compressor
attachment
Intake valve
90890-04114, YM-4114
Exhaust valve
90890-04108, YM-4108