Checking The Valves And Valve Guides - Yamaha YZF-R1S Service Manual

VALVES AND VALVE SPRINGS
4. Remove:
S upper spring seat 1
S valve spring 2
S valve stem seal 3
S lower spring seat 4
S valve 5
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:
S 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:
S valve guide
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.
a. Remove the valve guide with the valve guide
remover 1 .
b. Install the new valve guide with the valve
guide installer 2 and valve guide remover
1 .
c. After installing the valve guide, bore the
valve guide with the valve guide reamer 3 to
obtain the proper valve-stem-to-valve-guide
clearance.
5-28
ENG
Valve-stem-to-valve-guide
clearance
Intake
0.0010 X 0.0037 mm
(0.0004 X 0.0015 in)
<Limit>: 0.08 mm (0.0032 in)
Exhaust
0.025 X 0.052 mm
(0.0010 X 0.0020 in)
<Limit>: 0.10 mm (0.0039 in)