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How
do I bench-test the starter solenoid on my 75-hp two-stroke outboard?
M.L., via e-mail
Bench-testing
a starter solenoid is a relatively simple procedure, and while solenoid
styles vary from engine to engine, all solenoids have two large terminal
studs and two small terminal studs.
Begin
by disconnecting the negative battery cable from the battery. Next remove
all leads from the solenoid terminal studs. There is no need to remove
the solenoid from the engine. Connect an ohmmeter—calibrated on
the Rx1 scale—to the two large terminal studs (1 and 2 above, in
both illustrations). The ohmmeter should indicate no continuity, due to
the fact that no power is running through it. Replace the solenoid if
any other reading is noted.
Using
jumper cables, attach a 12-volt battery to the two small solenoid studs
(3 and 4, above)—polarity is not important. You should hear a click
as (or if) the solenoid engages, and the ohmmeter should indicate continuity.
This is because the solenoid is a high-amperage switch that when energized
shows a closed circuit. Replace the solenoid if any other reading is noted.
When
you are finished, replace all the leads and connect the negative battery
cable last.
I’m
having a steady misfire on my gasoline stern drive. What can I do to find
the problem? P.A., via e-mail
Start
the engine, and let it idle. Remove one spark plug wire at a time. If
the misfire worsens, that cylinder is operating correctly. Continue until
the misfire remains the same, indicating that cylinder is not operating
correctly. Check the condition of the spark plug and its gap, and examine
the spark plug wires for open cracks in the insulation. Also check your
distributor cap.
I
think I’ve got a voltage drop in the circuit that takes care of
my entertainment system. How do I test if this is the case? C.H.,
via e-mail
If
you think one of your components is experiencing a voltage drop, it is
most likely due to unwanted resistance in the circuit connections, switches,
or wiring. You can do a simple voltage-drop test to find the problem.
Here’s how.
Since
the circuit must be operating, turn on your entertainment system. Next,
set your multimeter to D.C. volts. As the component being tested must
be between the meter’s two probes, place one of the probes on one
side of the component and the other probe on the other side. If your meter
reads zero volts, the voltage drop does not exist at that component. Repeat
this procedure for every component on that particular circuit. A voltage
drop will be indicated when the meter reads voltage. Usually, depending
on load, a voltage drop greater than 0.5 volts indicates a problem.
As for
the culprit, long runs of undersized wiring can cause excessive voltage
drops, so check your wiring runs and, if necessary, increase the wiring
size. In addition, as heat is generated with voltage drops, you may want
to check your components for excessive heat. Once you’ve isolated
the culprit, have it cleaned, repaired, or replaced.
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