Cleaning; Inspection; Reassembly - Mercury MerCruiser MCM 454 Mag MPI Service Manual

SERVICE MANUAL NUMBER 23

Cleaning

IMPORTANT: DO NOT use grease dissolving solvents for cleaning over-running
clutch, armature and field coils. Such a solvent would dissolve grease packed in
clutch mechanism and damage armature and field coil insulation.

Inspection

With starting motor completely disassembled, except for removal of field coils, component
parts should be cleaned and inspected. Field coils should be removed only where defects
are indicated by tests. Defective parts should be replaced or repaired.
1. Test over-running clutch action. Pinion should turn freely in over-running direction and
2. Check that brush holders are not damaged or bent and will hold brushes against com-
3. Check brushes. Replace if pitted or worn to one-half their original length [5/16 in. (8 mm)
4. Check fit of armature shaft in bushing of drive housing. Shaft should fit snugly. Replace
5. Check fit of bushing in commutator end frame. If bushing is damaged or worn
6. Inspect armature commutator. If rough or out-of-round, turn down and undercut. Inspect

Reassembly

After all parts are thoroughly tested and inspected and worn or damaged parts replaced,
reassemble starter as follows:
1. Assemble brushes and related parts to field frame as follows:
2. Assemble over-running clutch assembly to armature shaft as follows:
Index
90-861326--1 MARCH 1999
Downloaded from https://needmanual.com/
must not slip in cranking direction. Check pinion teeth. Check spring for tension and
drive collar for wear. Replace if necessary.
mutator.
or less].
bushing, if worn. Apply SAE 20 oil to bushing before reassembly. Avoid excessive lubri-
cation.
excessively, replace end frame assembly. Apply SAE 20 oil to bushing before
reassembly. Avoid excessive lubrication.
points (where armature conductors join commutator bars) for good, firm connection.
Burned commutator bar usually is evidence of poor connection.
a. Assemble brushes to brush holders. Attach ground wire to grounded brush and field
lead wire to insulated brush.
b. Assemble insulated and grounded brush holders together with V-spring. Position as
a unit and install support pin. Push holders and spring to bottom of support and rotate
spring to engage center of V-spring in slot in support.
a. Lubricate drive end of armature shaft with SAE 10W oil.
b. Slide assist spring and clutch assembly onto armature shaft with pinion outward.
c. Slide retainer onto shaft with cupped surface facing end of shaft (away from pinion).
STARTING SYSTEM
Page 4A-9