Compression.

Compression.

5.2.2.2

5.2.2.2.1

R e m o v e Cylinder Head and Shield.

Always note the position of the different cylinder head screws so that they

may be properly reassembled. If a screw is used in the wrong position,

it may be too short and not engage enough threads or it may be too long

and bottom on a fin, either breaking the fin or leaving the cylinder head

loose.

5.2.2.2.2

I n s t a l l Cylinder Head and Shield.

Assemble the cylinder head with new head gasket, cylinder head shield,

and washers in their proper place. Do not use shellac or other sealer

on cylinder head gaskets. Tighten the screws down evenly by hand in

rotation, until they are snug against the washer or cylinder head. Use

a 1/2" socket wrench with a handle not over 6" long and tighten screws

about 1/4 turn. Do not turn one screw down completely before the others,

as it may cause a warped cylinder head. Run the engine 2 to 5 minutes.

Then tighten all screws snugly, (which will normally be about 1/4 turn).

To Reface Valves and Seats.

5.2.2.2.3

Faces on valves and valve seats should be resurfaced with a valve grinder

or cutter, to an angle of 45. Valve and seat should then be lapped with a

fine lapping compound to remove grinding marks and assure a good seat.

Valve seat width should be 3/64" to 1/16". If the seat is wider, a narrow-

ing stone or cutter should be used. If either the seat or valve is badly

burned, it should be replaced. Replace valve if margin is 1/64" or less

after refacing.

5.2.2.2.4

To Check and Adjust Tappet Clearance.

Insert the valves in their respective positions in the cylinder. Turn the

crankshaft until one of the valves is at its highest position. Then turn the

crankshaft one revolution. Check clearance with feeler gauge. See Table

1 . Repeat for other valve. Grind off the end of the valve stem if neces-

sary to obtain proper clearance.

N O T E : CHECK CLEARANCE COLD.

5.2.2.2.5

To Install Valves,

Some engine's use the same spring for intake and exhaust side, while others

use a heavier spring on the exhaust side. Compare springs before installing