Checking The Valve Seats - Yamaha YZF-R1P Service Manual

VALVES AND VALVE SPRINGS
EAS00240

CHECKING THE VALVE SEATS

The following procedure applies to all of the
valves and valve seats.
1. Eliminate:
• carbon deposits
(from the valve face and valve seat)
2. Check:
• valve seat
Pitting/wear → Replace the cylinder head.
3. Measure:
• valve seat width a
Out of specification → Replace the cylinder
head.
M MMM
a. Apply Mechanic's blueing dye (Dykem) 1
onto the valve face.
b. Install the valve into the cylinder head.
c. Press the valve through the valve guide and
onto the valve seat to make a clear impres-
sion.
d. Measure the valve seat width.
NOTE:
_
Where the valve seat and valve face contacted
one another, the blueing will have been
removed.
L LLL
4. Lap:
• valve face
• valve seat
NOTE:
_
After replacing the cylinder head or replacing
the valve and valve guide, the valve seat and
valve face should be lapped.
5 - 27
ENG
Valve seat width
Intake: 0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)
Exhaust: 0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)
<Limit: 1.6 mm> (0.063 in)
M MMM M M MMM M M MMM M M MMM M
L LLL L L LLL L L LLL L L LLL L
M MMM M MMM
L LLL L LLL