GENERAL - TM-55-4920-341-140057

SECTION III (Con't.)

GENERAL

Inspect- 50 100

ion

hour hour

Cylinder heads, manifold, and muffler. Inspect

the cylinder heads, manifolds and muffler for

leaks; loose mounting and defective gaskets.

Tighten loose manifolds and muffler mounting bolts

and nuts. During the first weekly servicing of a

new or reconditioned engine, inspect all the

cylinder head bolts for tightness. After warm-

ing engine up to operating temperature, tighten

any loose bolts to 25 to 32 ft-lb torque. Replace

defective cylinder head and manifold gaskets.

Valve mechanism. If the valves are noisy or loss

of power is noticed, inspect the condition of the

valve mechanism.

Remove valves covers and adjust valve lifter

clearance if necessary. The correct clearance

for the valve lifters is 0.0080 inch for the

intake valves and 0.0160 inch for the exhaust

valves. Replace cover gaskets if defective.

Compression Test. Remove the spark plugs and

test the cylinder compression by turning the eng-

ine over several times to stabilize gage reading.

If the gage reading varies more than 10 pounds

between the four cylinders, inspect the cylinder

head bolts for tightness.

Tighten any loose bolts and retest. If low com-

pression or a variation in compression persists,

the trouble lies with the cylinder head gasket,

valves, or piston rings. Correct all deficienc-

ies.

Electrical system magneto. Inspect the ignition

magneto for loose mounting bolts and wiring

connections. Correct any deficiencies noted.

Remove the end cap and inspect the distributor

cap for cracks, and corroded terminals. Examine

the breaker point gap. The correct gap is

0.015 inch at full separation of points.

Spark plugs. Inspect the spark plugs for loose-

ness, bad connections, and dirty or broken

insulators.

Replace damaged spark plugs. Clean dirty plugs

and set the gap to 0.0300 inch.

-49-