IGNITION SYSTEM REPAIR TIPS
The subject of the outboard ignition system could
fill a phone book! I will only try to give a general procedure to
follow here, the variety of systems used is boggling to the mind.
Keeps engineers busy I suppose.
The simplest system is the flywheel magneto. First
thing to have handy to service this is the correct type of flywheel
puller. All outboard flywheels are pulled from the center, under
no circumstances attempt to remove a flywheel by use of a gear puller
that hooks under the outside edge. You WILL ruin it!
Almost all ignition systems incorporate some sort
of a stop switch. The FIRST test of any system is to simply disconnect
this circuit AT THE SOURCE to determine if there is a simple short
in the wiring or switches. On most new CDI systems this wire has
been standardized as a black wire with a yellow stripe.
While we are on the subject of grounds, be sure
all the coil, CDI pack and mounting bracket ground leads are clean
and have continuity. If there's no ground, the system won't work.
On a magneto energized CDI system, take a visual
look at the stator up under the flywheel. Is it leaking honeylike
liquid potting compound onto the top of the block? Drips hanging
off the coils? Cracks/burned spots? Even if the electrical values
are on spec, a stator showing any of these symptoms is NO GOOD and
must be replaced. This applies to any other potted component as
There is a definite relationship between the charging
circuit and the ignition on all CD systems. It is IMPERATIVE that
all battery connections be clean and tight. I recommend a marine
type battery with threaded posts to accept your battery cables.
Toss the wing nuts and use stainless steel elastic lock nuts. Mount
excessive accessory leads on a separate terminal; many newer marine
batteries have 2 on each side. Test the rectifier/regulator to be
sure the system is charging.
An inoperative charging system will
cause an otherwise good stator to overheat causing it to fail.
WARNING! These systems carry up to 300VAC in the primary
and some 45,000 in the secondary.
Extreme caution is a MUST when
all ignition coil and powerpack tests on an insulated or wooden bench top.
not handle CDI powerpack or ignition coil output leads during any
type of output test.
not touch any of these leads when the engine is cranking or running.
cover is a machinery guard. Use caution when conducting tests on
a running engine.
CAREFUL. Other hazards may exist,
you should be aware at all times.
IF you wish to service or repair your own
ignition system, I HIGHLY RECOMMEND you obtain a
service manual to help you.
We have most linked RIGHT
HERE at Mastertech.
Meanwhile, you can check out this Troubleshooting Precedures guide from CDI Electronics for some test procedures for various ignition systems.