Cracked coils ?

[sbrown21]

I checked coils on a wizard outboard , bad at the plug wires. When I pulled the flywheel the coils were badly cracked so I ordered a new pair from Jim. Then I pulled the push in spark plug wires and behold the coils tested good. I sealed the crack’s with clear nail polish and epoxy added new wires than put them all back together. I am showing good spark . Question – Will the repaired coils last any length of time or should I go ahead and replace the old coils? The Bendix coils are a little pricey. Thank’s

[wedgie]

I would replace the coils if it were mine. Not worth taking a chance of them failing while 10 miles out at sea. 😮

[Doug Wilson]

If it was me would go ahead and replace them. If they were that cracked, may work for now but the plastic will keep
cracking and most likely will leave you stranded on the water, usually when you are a long way from the dock
and nobody is around. I know the coils are not cheap, but to me not worth the risk of future problems.

Doug

how is it motors multiply when the garage lights get
turned off?

[crosbyman]

new coils or pair of oars …. your call !

Joining AOMCI has priviledges 🙂

[brian]

Every time you leave the dock you’ll hear that little voice asking if this is the time for the coils to die. Don’t let that little voice talk, replace the coils. I have cracked coils I’ve left in a motor I run only in the test tank. So far they still fire, but I expect them to go belly up at any time, especially if I were to put that motor on the boat.

[garry-in-michigan]

My Big Twin was showing intermittent spark when I decided to put it back in service after 40 years in storage. I had been pulling the plugs and squirting fogging air in the cylinders while cranking it with a spark tester attached to the spark plug wires every couple years. The spark always looked good. I thought it was about time to clean and adjust the points.

I was SHOCKED at the total disaster I found under the flywheel. Broken plastic everywhere. The plastic sand had gouged the breaker cam and I could see carbon tracks where the spark had been jumping across the gaps in the insolation.

It was found that the first plastic covered coils melted with heat and age. So starting in the mid ’50s more hardener was added to the mix. My Big twin is testament to what happened then. The coils are built in a "Clean Room". The air is dehumidified and filtered. The coil molds are put in a vacuum chamber and then the liquid plastic is drawn in by the vacuum.

If the coil becomes unsealed, dust and dirt enevenably follow. With the heating and cooling of service these microscopic bits erode the insulting paint on the magnet wire causing microscopic shorts which reduce voltage. The sealing paint you add to the cracks also seals in the dirt already there . . . It is only a matter of time. . . 🙄

[jw-in-dixie]

A homemade coil tester you might be interested in. Used a old phonograph motor with a hex nut attached to the shaft operating the points on a 60s GMC distributor plate. Has an on-board coil and cond for testing plugs. Jumpers to connect to the unknown coil. Can run a coil for a few minutes, hours, days or weeks, if you like. If the OBM has exposed kill connection(s), using longer jumpers the coils can be tested in place without pulling the flywheel. Adjustable DC input. Can add heat with a hair drier to stress the insulation. Works for me. 😉

[Mumbles]

When they are cracked, they are done!. Time for replacements!

---

Attachments:

[2fast4me]

If it runs with the coils repaired as you have described I would run the motor and see "what else is broke". No point in investing in new ignition components in your case maybe $100.00 if the power head or lower unit are uservicable. Then if everything Checks out do your rebuild. That’s my take on it. Mumbles is right about OMC coils replace them there cheap. Bendix or Phelon coils, to rich for my blood i’ll try to repair them first. Jim

2Fast4Me

[The Boat House]

I found this coil in a KF7. The other
looked fine. Its not a problem for
me so I got a new set of coils from
Jim ($110.00). But I put some liquid
tape on this crack and I’m going to
run the old ones to see what happens.
Will also pull the flywheel from time to
time to see if new cracks are appearing.
If one drops out I have a set to replace
them. There was a time when it would
have had to run on the old coils cause
there was no money for new ones.
Economics often determines the
best solution at the time.

[Author]

Posts