c. Refinish machined mating surfaces and
g. Install new gaskets and seals during
valve seats on block with fine emery cloth.
4 . Governor.
To repair governor, proceed
d. Refinish seating surfaces on valves with
fine emery cloth.
a. Disassemble governor.
e. Valves that show evidence of burning
must be replaced with equivalent parts in service-
b. Replace damaged gear.
c. Replace defective bearings.
f. If valve seats in block are burned, they
d. Replace worn flyweight pivot pins.
must be machined either .020" or .040" and
oversized valves of commensurate size installed.
e. Replace threaded fittings if threads are
g. A cracked block must be replaced by one
in serviceable condition.
f. Reassemble governor.
h. Reassemble cylinder block.
5. Cylinder Head. To repair cylinder head,
proceed as follows:
7. Crankcase Assembly. To repair crankcase
assembly, proceed as follows:
a. Clean cylinder head thoroughly.
a. Remove oil pan and gasket.
b. Clean machined mating surfaces of all
remaining particles of gasket material.
b. Clean all parts thoroughly.
c. Refinish machined surfaces with fine
c. Ruptured oil pan must be replaced with
emery cloth to remove minor scratches.
one in serviceable condition.
d. If cylinder head has deep scratches in
d. All studs with damaged threads must be
machined surfaces or is cracked, it must be re-
replaced with serviceable studs.
placed with a head in serviceable condition.
e. If crankcase is cracked, replace it with
6. Cylinder Block and Components. To re-
a unit in serviceable condition.
pair cylinder block and components, proceed
f. Replace damaged piston, connecting rod,
or connecting rod bearing.
a. Remove valves and valve springs from
g. Replace worn piston rings.
h. Reassemble crankcase assembly.
b. Clean parts thoroughly.
REASSEMBLY AND ALIGNMENT
a . Feed new ignition wire through clip re-
4.18. GENERAL. The reassembly and align-
moved from old ignition wire.
ment of components described in this section are
arranged in the same functional sequence as de-
b. Attach each ignition wire in proper order;
scribed in Section III of Chapter 4.
taking length into consideration from spark plug to
magneto terminal and secure nut of each wire to
4-19. ELECTRICAL SYSTEM. To install the
appropriate terminal on magneto.
components of the electrical system proceed as
c. Screw nut on opposite end of ignition
were to appropriate spark plug and secure
1. Ignition Wire Assembly. To install the
ignition wire assembly proceed as follows: