Section XI. MAINTENANCE OF IGNITION SYSTEM

(4) Use a rope sling and support the weight of

the radiator with a hoist before removing the nuts (12)

and lock washers (13) that secure the radiator (20) to

the engine support; remove the radiator.

b. Cleaning and Inspection.

(1) Thoroughly flush the radiator with water,

both inside and out. Make sure all bugs and debris are

removed from the cooling fins.

(2) Inspect the radiator for cracks, damaged

cooling fins, leaking tubes, leaks around the top bonnet,

and other damage. Refer a damaged radiator to direct

support maintenance for repair.

(3) Inspect the fan guard and fan shroud for

cracks, broken weldments, distortion, and other

damage. Replace damaged parts.

c. Installation.

(1) Installation is the reverse of the removal

procedure. Refer to figure 4-20.

(2) Install the coolant and oil cooler lines and

fittings (para 4-29).

(3) Install the engine housing panels that

were removed to provide access to the radiator (para 4-

20c).

(4) Service the engine coolant system end

the engine oil system. Start the engine and check for

leaks. Correct any deficiencies.

1. Cap screw

11. Fan shroud

2. Flat washer

12. Nut

3. Fan guard

13. Lock washer

4. Machine screw

14. Liner

5. Lock washer

15. Nut

6. Radiator support

16. Lock washer

7. Radiator support

17. Crank support

8. Machine screw

18. Spacer

9. Lock washer

19. Radiator cap

10. Flat washer

20. Radiator

Figure 4-20. Radiator and related parts, exploded

view.

Section XI. MAINTENANCE OF IGNITION SYSTEM

delivered to each spark plug. An improperly timed

4-32. Description

magneto will make engine operation impossible.

a. The ignition system includes the magneto (11,

fig. 4-8) and radio-surpressed spark plugs (1) which

c. The magneto consists of a magneto rotor which

have shielded cables (5). The system is completely

is rotated in a laminated frame to set up magnetic flux in

independent of the battery- and alternator-powered

the laminated frame. This induces a current in the

electrical system.

primary winding each time the magnetic flux rises and

falls. The primary winding acts as the primary winding

b. The magneto is timed t) the engine and is

of a step-up transformer, surrounded by the secondary

driven by the camshaft gear through the governor drive

coil. Breaker point opening occurs at the instant of

gear which is engaged by the drive lugs on the magneto

maximum primary current, causing an immediate

drive coupling. There is a critical timing relationship

collapse of the magnetic field. This collapsing magnetic

between these driving parts since it determines the

field induces an extremely high voltage surge through

instant at which the spark from the magneto will be

the secondary circuit. The capaci-

4-23