Cleaning and Inspection. - TM-5-4320-272-120061

(1) Disassemble magneto as you would to

(2) Disconnect the ground switch lead (10)

remove breaker points; refer to subparagraph b

from the capacitor (25). Remove the capacitor and

above, steps (1) through (3).

preformed packing (26) from the end cap

(2) Remove distributor rotor (29) from

assembly.

Discard both the capacitor and

distributor gear assembly.

preformed packing.

( 3 ) Remove the distributor block (28) by

( 3 ) Remove the screws (33 and 35), flat

removing four screws (27) securing block to the end

washer (34), and retaining ring (32) that secure the

cap.

breaker point assembly (37) and cam wick (36) to

e. Cleaning and Inspection.

the bearing support. Remove the breaker point

WARNING

assembly.

Clean all parts in a well-ventilated area.

(4) Inspect the breaker points for evidence of

A v o i d inhalation of solvent fumes and

pitting or pyramiding. You can use a small tungsten

prolonged e x p o s u r e o f t h e s k i n t o

file or fine stone to resurface the points. You must

cleaning solvent. Wash exposed skin

replace badly worn or pitted points.

thoroughly.

(5) Install new or resurfaced breaker point

(1) If a repair kit is available and is being

assembly on bearing support, using the screws (33

installed, discard all removed parts which have

and 35), flat washer (34), and retaining ring (32).

replacements in the kit. Clean the loose metallic

Leave the mounting screws just loose enough to

parts with cleaning solvent (fed. spec. P-D-680);

permit adjustment. Be sure you install the cam

dry thoroughly. Clean the remaining parts with ac

wick (36).

cloth dampened lightly with solvent. You must take

(6) Rotate the engine by hand to locate the

care not to saturate the coil in the magneto housing.

breaker arm on the high point of the cam. Using a

(2) Inspect the end cap for cracks, burned

feeler gage, set the breaker point at maximum

terminals, signs of arcing, and other damage.

opening of 0.015 inch. Make the adjustment with a

( 3 ) Rotate the rotor shaft and check for

screwdriver inserted into the slot at the bottom of

binding or rough operation. Check for play between

the contact plate, and pivoting between the two

the shaft and bearings. Replace the magneto if

small bosses on the bearing support. Hold the parts

more than just perceptible play exists.

in place while you tighten the mounting screws.

(4) Inspect the magneto gear (41) for worn,

Make a final check of the breaker point gap to be

cracked, or broken teeth.

sure you have maintained the correct adjustment.

(5) Inspect the magneto housing for cracks,

(7) If the cam is dry, coat it with a light coat

distortion, and damaged threads. Check that the

of grease.

coil is firmly wedged in the frame. Check the coil

(8) Before you reinstall the end cap, clean the

for damaged insulation, gouges, and other damage.

contact surfaces between the cap and the housing.

(6) If you find parts damaged that are not

Using a new gasket (24), mount the end cap on the

i n c l u d e d in the repair kit, replace with a new

housing. Make sure the high tension lead (39) and

magneto assembly.

insulator (38) are properly installed before securing

f. Reassembly. During reassembly, install all of

cap. Secure end cap to housing with screws (21 and

the new parts that are contained in your repair kit,

22). Make sure the ground strap (13) is mounted to

to replace the parts which were removed from the

the magneto by screw (22).

magneto. Reassembly is essentially the reverse of

(9) Install new capacitor (25) and preformed

disassembly. Refer to figure 4-9. Note the

packing (26).

following:

c. Removal. Remove the magneto for servicing

(1) Before you install the end cap, make sure

or replacement as follows:

the high tension lead (39) is properly installed in

(1) Disconnect the shielded spark plug cables

the distributor block and in the receptacle in the

( 4 , 5, 6, and 7, fig. 4-9) from the magneto.

coil.

D i s c o n n e c t the ground switch lead (10) and

(2) Install and adjust the breaker point

disconnect ground strap (13) by removing screw

a s s e m b l y (37) as directed in subparagraph b

(11) and lock washer (12).

above.

(2) Remove the cap screw (16), lock washers

g. Installation and Magneto Timing. Timing the

(15 and 17), and nut (14). Remove nut (18) and

magneto to the engine is a critical step of in-

l o c k washer (19). Now you can withdraw the

stallation procedure. Install and time the magneto

magneto and gasket (20) from the gear housing.

as follows:

d. Disassembly. Disassemble the magneto only

(1) Remove the screen over the flywheel air

far enough for you to install the parts included in

intake opening by removing the screws holding the

the major repair kit, following the sequence in-

screen in place. This will expose the timing marks

dicated in figure 4-9. Pay particular attention to the

on the flywheel and shroud. Refer to figure 4-10.

following:

4-21