80
POWERHEAD
CYLINDER HEAD
Cleaning and Inspection
IMPORTANT:
If any excessive wear, cracks,
defects, or other damage is found on any compo-
nent, replace.
Cylinder Head
Remove all carbon from the combustion chamber.
IMPORTANT:
Do not use any sharp edged tool
to scrape carbon off the cylinder head or compo-
nents. DO NOT scuff or nick the metal surfaces
when decarboning.
Inspect the cylinder head for crack in the intake
and the exhaust ports, the combustion chamber
and the head surface.
Valve Seat
Inspect the valve seats for cracks or other dam-
age.
Cylinder Head Distortion
Using a straightedge and thickness gauge, mea-
sure the gasket surface of the cylinder head at six
locations as shown.
Cylinder head distortion:
•
Service limit: 0.002 in. (0.05 mm)
If the measurement exceeds the service limit,
resurface or replace the cylinder head.
IMPORTANT:
The cylinder head can be resur-
faced using a surface plate and a #400 grit wet
sandpaper. Move the cylinder head in a figure
eight pattern when sanding.
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