TM 5-4310-227-15
(11) H o l d the magneto upright, in the
4-20. Starter (Model BMW-452ENG)
normal position and rotate the im-
a. Removal and Installation. Remove
pulse coupling clockwise until the
pawl on the coupling hub engages the
b. Disassembly. Disassemble starter in nu-
pawl stop pin (43). The two drive
merical sequence of parts as illustrated in fig-
lugs on the coupling shell (35) should
ure 4-2. Due to the method of installing field
now be in a vertical position.
coils and other components in the frame and
(12) I n s t a l l the sleeve nut (32) on the
field or fungus resistant assemblies, it is nec-
rotor.
essary to replace the frame and field assembly
(13) P o s i t i o n the 2 shims (29) on the
as a unit, if field coils are required.
r o t o r and install the rater sleeve
c. Cleaning, Inspection, Testing and Repair.
bearing (24) in the bearing support
(1) Clean all metal parts except the drive
plate assembly (26). Secure the sup-
assembly in an approved cleaning sol-
port plate to the frame with the 4
vent and dry thoroughly.
screws (25).
(2) Clean the armature with a clean cloth
(14) Secure the coil slip (2) to the magneto
dampened with an approved cleaning
coil (1) with the screw (3). Secure
solvent and dry with low pressure,
the coil in the frame (44) by install-
compressed air. Inspect the comutator
ing the setscrews (45).
f o r rough spots, scoring, pitting,
(15) Secure the capacitor (4) to the bear-
burned, or out of-round condition. If
ing support plate assembly (26 ) with
the commutator is worn, burned, or
the screw (5).
rough, place the armature in a lathe
(16) Install the cam with holder (11) on
and take light cuts on the commutator
the contact set support plate and se-
until the condition is corrected. Un-
cure the contact set support plate to
dercut the mica to a depth of 1/32 to
the bearing support plate assembly
3/64 inch. Smooth the commutator
(26) with the two screws (10 and
with No. 00 sandpaper and blow off
13), and flat washers (6 and 12)
particles with low-pressure, com-
(17) Position the breaker arm and spring
pressed air.
(9) on the fulcrum pin in the bearing
(3) Use a growler to test the armature for
support plate
assembly (26). In-
a short winding. Position the arma-
stall the fulcrum retaining ring (8)
ture on the growler and energize the
on the fulcrum pin.
growler. Hold a thin, steel strip par-
(18) Secure the breaker arm and spring
allel to the core slots and explore the
(9), coil lead, and capacitor lead to
exposed surface of the armature core.
the contact set support plate with the
A short - circuited coil in one of the
terminal screw (10).
s l o t s , bridged by the jaws of the
(19) Position the spring (20) on tthe push-
growler, will cause the steel strip to
button (21) and position the push-
vibrate when brought close to the oth-
button in the bushing (19). Secure
er slot occupied by the defective coil.
by installing the ground switch re-
Turn the armature in the growler one
taining ring (18) on the pushbutton.
slot at a time and continue to explore
with the steel strip until all coils
(20) Position the ground switch assembly
have been tested. Replace a defective
in the ignition shield (16) and secure
armature.
with the knurled nut (22).
Caution: In the following open the
ground tests, do not touch the test
probes to the shaft bearing surfaces
or the commutator brush surfaces.