Checking The Cylinder Head - Yamaha PW50W 2007 Service Manual

CYLINDER HEAD, CYLINDER AND PISTON
2. Remove:
9 Top ring
9 Second ring
(with expander ring)
NOTE:
When removing a piston ring, open the end
gap with your fingers and lift the other side of
the ring over the piston crown.

CHECKING THE CYLINDER HEAD

1. Eliminate:
9 Combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid dam-
aging or scratching.
9Spark plug bore threads
2. Eliminate:
9 Exhaust port carbon deposits
(with a rounded scraper)
3. Check:
9 Cylinder head
Damage/scratches → Replace the cylin-
der head.
4. Measure:
9 Cylinder head warpage
Out of specification
cylinder head.
Warpage limit
0.03 mm (0.0012 in)
5-11
ENG
→ Resurface the