Yamaha TW200 Service Manual page 105

INSPECTION AND REPAIR
I
ENG
I' ..
I
-Turn the valve until the valve face and valve
seat are evenly polished, then clean off all
compound.
NOTE: _
To obtain the best lapping results, lightly tap -
the valve seat while rotating the valve back and
forth between your hands.
-Apply a fine lapping compound to the valve
face and repeat the above steps.
NOTE: _
Be sure to clean off all compound from the
valve face and valve seat after every lapping
operation.
-Apply the Mechanic's bluing dye (Dykem) to
the valve face.
-Install the valve into the cylinder head.
- Press the valve through the valve guide and
onto the valve seat to make a clear pattern.
-Measure the valve seat width again.
If the valve seat width is out of specification,
reface and lap the valve seat.
Valve Spring Free Length:
VALVE SPRING
1. Measure:
-Valve spring free length
®
Out of
specification~Replace.
Outer spring
36.6 mm (1.44 in)
Inner spring
36.2 mm (1.43 in)
302-005
302-006
2. Measure:
-Valve spring installed force
@
Out of
specification~
Replace.
@
Installed length
~
Valve Spring Installed Force:
Inner spring
Outer spring
@ @
@
@
30.5 mm 8.3-10.3 kg 32.0 mm 16.5 - 20.5 kg
(1.20 in) (18.5-22.7Ib) (1.26 in) (36.4-45.2Ib)
4-25