Mercury 40 Service Manual page 225

Cylinder Head
1. Inspect the cylinder head for the following conditions:
2. Inspect cylinder head for warpage. Replace cylinder head If out of specification.
Valve Guides
NOTE: Inspect the valve guides for wear or damage. If valve guide wear is out of specifica-
tion, replace the valve guide.
Measure valve guide bore.
a
90-828631R3 MARCH 1999
Mineral deposits/corrosion in water passage ways.
Carbon Deposits In Combustion Chamber (use round scraper to clean away
deposits). Be careful not to scratch or remove material.
Cylinder Head Warpage Limit
0.004 in. (0.1 mm)
Valve Guide Inside Diameter
Intake Valve
Exhaust Valve
53736
0.2165 - 0.2170 in.
(5.500 - 5.512 mm)
CYLINDER HEAD
Page 4A-29