TROUBLESHOOTING 29
Loud
grinding noises when starter runs
Solenoid
(S) terminal
Ammeter
~
- +
Starter
motor
Voltmeter
~
+ -
+
12
volt
battery
This can be caused by improper meshing
of
the starter
pinion and flywheel ring gear or by a broken overrunning
clutch mechanism.
1. Remove the starter. See Chapter Nine.
2. Check the starter pinion gear. If the teeth are chipped
or worn, inspect the flywheel ring gear for the same prob-
lem. Replace the starter and/or ring gear as required.
3. If the pinion gear is in good condition, the overrunning
clutch mechanism in the starter may be defective. Replace
the starter with a new or rebuilt marine unit.
Starter
Solenoid Resistance Tests
Check the starter solenoid using the following resis-
tance tests:
open circuit or a loose connection. If the engine does not
start, replace the starter solenoid.
Starter spins
but
does
not
rotate flywheel
1. Remove the starter. See Chapter Nine.
2. Check the starter pinion gear. If the teeth are chipped
or worn, inspect the flywheel ring gear for the same prob-
lem. Replace the starter and/or ring gear as required.
3. If the pinion gear is in good condition, disassemble the
starter and check the armature shaft for corrosion. See
Brush Replacement, Chapter Nine, for the disassembly
procedure.
If
no corrosion is found, the starter drive mech-
anism is slipping. Replace the starter with a new or rebuilt
marine unit.
Starter will
not
disengage when start switch is released
This problem is usually causedby a sticking solenoid or
defective start switch, but the pinion may
jam
on the fly-
wheel ring gear on an engine with many hours
of
opera-
tion.
NOTE
A low battery or loose or corroded battery
connections can also cause the starter to re-
main engaged with the flywheel ring gear.
Low voltage at the starter can cause the
contacts inside the solenoid to chatter and
weld together, resulting in the solenoid
sticking in the ON position.
CAUTION
Disconnect the negative battery cable be-
fore
performing resistance tests.
I. Refer to
Figure
2 and connect an ohmmeter lead to the
S terminal
of
the solenoid. Connect the remaining ohm-
meter lead to the metal body
of
the solenoid. The ohmme-
ter should indicate approximately one ohm or less.
Replace the solenoid
if
the ohmmeter indicates infinite re-
sistance (no continuity).
2. Refer to
Figure
3 and connect an ohmmeter lead to the
S terminal
of
the solenoid. Connect the remaining ohm-
meter lead to the M terminal
of
the solenoid. The ohmme-
ter should indicate approximately one ohm or less.
Replace the solenoid
ifthe
ohmmeter indicates infinite re-
sistance (no continuity).
Starter
Motor
No-Load
Current
Draw
Test
If troubleshooting indicates that the starter motor may
be defective, use the following starter motor no-load cur-
rent draw test to determine
if
the starter motor is in accept-
able operating condition.
To perform the test, the following equipment is needed:
an ammeter capable
of
measuring 0-100 amps, a voltme-
ter, a vibration tachometer and a fully charged 12-volt bat-
tery. Minimum battery capacity is 70 amp-hours for one-
and two-cylinder engines and 100 amp-hours for
three-cylinder engines.
1. Remove the starter motor from the engine. Securely
fasten the motor in a vise or other suitable holding fixture.
2. Using a heavy gauge jumper cable, connect the amme-
ter in series with the positive battery terminal (Figure 4).
Connect a voltmeter to the battery.
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