Cleaning And Inspection - Mercury MerCruiser MCM 454 Mag MPI Service Manual

SERVICE MANUAL NUMBER 23

Cleaning and Inspection

1. Clean all parts with a clean, soft cloth. DO NOT use solvent, or electrical components
2. Inspect the following parts for wear and damage:
Index
90-861326--1 MARCH 1999
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may be damaged.
a. Brush/regulator assembly - inspect for cracked casing, damaged brush leads,
poor brush lead solder connections, weak or broken brush springs or worn brushes.
Replace brush set if brushes are less than 1/4 in. (6 mm) long.
b. Rotor - inspect for stripped threads, scuffed pole piece fingers or damaged bearing
surfaces (because of bearing turning on shaft).
c. Rotor-slip rings - clean slip rings with 400 grain (or finer) polishing cloth while spin-
ning rotor in a lathe. Blow off dust with compressed air. Inspect slip rings for grooves,
pits, flat spots or out-of-round [.002 in. (0.051 mm) maximum] and replace rotor, if
present.
d. Rotor shaft and front end bearings - inspect for damaged seals, lack of lubrica-
tion, discoloration (from overheating) and excessive side or end play. Bearing
should turn freely without binding or evidence of rough spots.
e. Stator - inspect for damaged insulation or wires; also inspect insulating enamel for
heat discoloration, as this is usually a sign of a shorted or grounded winding or a
shorted diode.
f. Front and rear end frames - inspect for cracks, distortion, stripped threads or wear
in bearing bore (from bearing outer race spinning in bore). End frame(s) MUST BE
replaced, if bearing has spun. Also, inspect bearing retainer recess in front end
frame for damage.
g. Fan - inspect for cracked or bent fins, broken welds (bi-rotational fan only) or worn
mounting hole (from fan spinning on shaft).
h. Pulley - inspect pulley mounting bore end for wear. Inspect drive surface of pulley
sheaves for trueness, excessive wear, grooves, pits, nicks and corrosion. Repair
damaged surfaces, if possible, with a fine file and a wire brush or replace pulley, if
beyond repair. Drive surfaces MUST BE perfectly true and smooth or drive belt wear
will be greatly accelerated.
CHARGING SYSTEM
Page 4C-19