Yamaha TT-R125LW, Owner'S Service Manual

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ENG
CYLINDER HEAD
4. Remove:
●
Bolt (camshaft sprocket) 1
●
Camshaft sprocket 2
NOTE:
Attach a wire
a
to the timing chain to prevent
it from falling into the crankcase.
5. Remove:
●
Bolts (cylinder head)
●
Cylinder head
NOTE:
●
Loosen the bolts 1/4 turn each and remove
then after all are loosened.
●
Loosen the bolts starting with the lowest
number one.
INSPECTION
Cylinder head
1. Eliminate:
●
Carbon deposits (from the combustion
chambers)
Use a rounded scraper.
NOTE:
Do not use a sharp instrument to avoid dam-
aging or scratching:
●
Spark plug threads
●
Valve seats
2. Inspect:
●
Cylinder head
Scratches/damage
→
Replace.
3. Inspect:
●
Cylinder head warpage
Out of specification
→
Re-surface.
Warpage measurement and re-surfacing
steps:
●
Attach a straightedge and a thickness
gauge on the cylinder head.
●
Measure the warpage.