Westerbeke 20B TWO Tehnical Manual page 78

2. Inspecting the armature.
a. Check the armature with a growler tester. If it's
short circuited, replace the armature. Also, check
for insulation between the commutator and its
shaft. If poorly insulated, replace the armature.
b. Measure the commutator 0.0. and the depth of
undercut. Repair or replace it if the service limit
is exceeded. Also, check the commutator out-
side surface for dirtiness and roughness. If
rough, polish the commutator with fine-grain
sandpaper.
3. Brush holder inspection.
a. Check the brushes. If worn out beyond the ser-
vice limit, replace the brushes.
b. Check the brush spring tension. If decreased
beyond the service limit, replace the springs.
c. Check for insulation between the positive brush
holder and holder base. If poorly insulated,
replace the holder assembly. Also, check the
brush holders for proper staking.
4. Field coil inspection.
a. Check for insulation between one end (brush) of
coil and yoke.
b. Check for conduction between both ends
(brushes) of coil.
c. Check the poles and coil for tightness.
Starter Adjustment and Assembly
Reassembly the starter assembly in the reverse order
of disassembly, giving care to the following:
1. Pinion shaft end play adjustment. Set the end play
(thrust gap) to 0.5 mm or less by inserting an adjust-
ing washer between the center bracket and reduc-
tion gear.
a. Fit the pinion shaft, reduction gear washer and
snap ring to the center bracket.
Westerbeke Engines 76
Checking Armature Coil
Checking Field Coil
Adjusting Gear
washer
O.5mm maximum
- - f l .. - -
Adjusting Pinion Shaft End Play