Yamaha MM600D, Manual

Page: 162 / 282

the commutator serviced by a dealership or electrical re-
pair shop.
8. Inspect the commutator copper bars (Figure 24) for
discoloration. If a pair of bars is discolored, grounded ar-
mature coils are indicated.
9.
Measure the commutator outside diameter with a ver-
nier caliper and compare to specifications in Table 3. Re-
place the commutator if the outside diameter meets or
exceeds the wear limit.
10. Use an ohmmeter and check for continuity between
the commutator bars
(Figure 26); there should be conti-
nuity between pairs of bars. Also check for continuity be-
tween the commutator bars and the shaft
(Figure
27);
there should be no continuity. If the unit fails either of
these tests the armature is faulty and must be replaced.
Starter Relay Replacement
The starter relay is mounted next to the battery (Figure
28). Open the shroud. Label and disconnect all wiring at
the starter relay assembly and remove starter relay.
Reverse to install.
SWITCHES
Switches can be tested for continuity with an ohmmeter
(see Chapter One) or a test light at the switch connector
plug by operating
switch in each of its operating posi-
tions and comparing results with the switch operation. For
example,
Figure 29 shows a continuity diagram for the
engine stop switch. It shows which terminals should show
continuity when the switch is in a given position.
When the engine stop switch is in the OFF position,
there should be continuity between the black and
wire terminals. This is indicated by the line
on the continuity diagram. An ohmmeter connected be-
tween these two terminals should indicate little or no re-
sistance and a test lamp should light. When the engine
stop switch is in the ON position, there should be no
nuity between the same terminals.
Off
If the switch or button does not perform properly, re-
place it. Refer to Figure 30 when testing the switches.
Perform the following when testing a switch:
NOTE
The throttle and carburetor switches are
part of the throttle override system. Refer
to