Spark Plugs and Cables

(3) Use a fine mill file and file electrodes to pro-

f. Coil Primary Continuity Test. Connect an ohm-

vide a square or flat surface at gap area.

meter across the primary ignition coil terminals. Do

(4) Clean all grease, dirt, and paint from ex-

not turn ignition switch to ON position. Check ohm-

posed insulator surface.

meter. Ohmmeter reading should be steady. If ohm-

d. Adjustment.

meter fluctuates, replace ignition coil. Disconnect

(1) Adjust spark plug gap by bending outside

ohmmeter.

electrode. Do not bend center electrode.

g. Coil Secondary (High Tension) Continuity Test.

(2) Use a round wire feeler gage to measure gap

Disconnect high tension wire from top of ignition

between electrodes. Adjust gap to 0.025 inch.

coil. Connect an ohmmeter across the high tension

e. Testing. Test all spark plugs after cleaning and

terminal at top of ignition coil and to the primary

adjusting; test all plugs in a standard spark plug

terminal to distributor. Ohmmeter should read less

than 20,000 ohms of resistance. If reading exceeds

machine. Discard all plugs showing an unsatis-

this value, replace ignition coil. Disconnect ohm-

factory test.

f. Installation

meter and connect high tension wire to ignition coil.

(1) Install spark plugs in wells in cylinder head.

3-46. Spark Plugs and Cables

Use new copper gaskets for all plugs.

a. General. Keep spark plugs and spark plug cables

(2) Tighten plugs by hand and then torque

in good condition and keep them free of dirt and

tighten plugs to 15 to 20 foot pounds.

grease. Replace any burned, cracked, or broken spark

(3) Refer to paragraph 3-24 to install bracket and

plugs or cables.

spark plug cables. Connect cables to spark plugs.

b. Removal.

3-47. Battery and Cables

(1) Disconnect cables from spark plugs. Blow out

a. Removal. Refer to figure 3-37 and remove the

dirt from spark plug wells with compressed air.

battery as follows:

(2) Refer to paragraph 3-24 to remove spark plug

(1) Disconnect battery ground cable (negative

cable bracket and cables from cylinder head.

post) and battery positive cable from battery. Use a

(3) Use a suitable spark plug socket wrench and

cable terminal puller tool to remove cables to prevent

remove spark plugs from cylinder head. Use correct

damage to battery.

fitting socket to prevent damage to spark plug.

(2) Remove wing nuts, flat washers, and lock

(4) Remove copper gasket from spark plug well

washers, securing battery hold-down to studs. Re-

after removing spark plugs.

move hold-down from battery.

c. Cleaning.

(3) Lift battery from battery box using a suitable

(1) Scrape carbon and lead deposits from elec-

lifting tool.

trodes and insulator body of plugs.

(2) Sand blast electrodes on plug with care. Do

not leave plug in sand blast machine too long. Dam-

age to glaze on insulator material could result.

3-35