Potted cable repair

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mbaird

mbaird

mbaird
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Not a Mopar but we have so many smart members.

So I am restoring an old Maico dirtbike with a Motoplat ignition and the spark plug cable broke off at the base where it goes into the coil . Anyone know how to repair this ?



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Insure good electrical connection, then:

There are special epoxies for potting electronics. Might get by with some clear from store.

Super glue and baking soda will make an instant fix. Squirt in a small amount, sift in pinch of baking power with two fingers, repeat. Keep nose, eyes and fingers away. Goggles, vinyl gloves. Sets up rock hard, similar to glass.

Also suitable electronic type RTV, it is flexible. Might be first choice. Don't use acetic acid cure silicone, it will corrode electrical connection.
 
I was thinking of using an electrode out of a spark plug by sharpening the tip and inserting it down thru the core of the cable remnant . Then epoxy and coat with liquid electrical tape or such . Then I can make a new ignition cable with 2 ends.
 
Kapton tape is much better. Electrical tape is a mess. A small brass tube from hobby store would make an inny, a sharp point is an outty, won't mate. But uncertain sex of remnant.

Might be able to find "coil on plug" solution from modern engine, and mount that. I just bought a set of 8 for about $35 shipped. For some evaluation testing.
 
These are A/C coils I am told .
Good advice on the copper tubing .
I just happen to have some .

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My experience is they screw on, There is a threaded wire post in the coil and the plug wire screws on to it.

I put 4 of these on my old Yamaha.

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This might be time for my lifelong philosophy

"You cannot break it if it's broken
But you can fix it so it cannot be fixed."

I've "fixed" a few things..................
 
Yep, I've fixed a "few" things also. It involved a BFH & the offending part after multiple times trying at repairing said part. LMAO
 
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Here is a DG511 ignition coil. The coil body as about 2"x2" excluding mount and connector. The primary resistance is 0.5 Ohms, inductance 1.5mH. The secondary HV terminal looks like 0.187 Fast-On tab. The OD will mate with spark plug boot. Connectors are available, but they cost as much as coils. Junk yard good option. With connector and Fast-On terminals, and bracket for easy install.

I purchased 8 for $35 shipped. I will do more tests. I used similar DG508 for a COP ignition, but it was angled. The DG511 is straight and does not require cutting and mods. The electrical characteristics were excellent.
 
Last edited:
KitCarlson said:
Here is a DG511 ignition coil. The coil body as about 2"x2" excluding mount and connector. The primary resistance is 0.5 Ohms, inductance 1.5mH. The secondary HV terminal looks like 0.187 Fast-On tab. The OD will mate with spark plug boot. Connectors are available, but they cost as much as coils. Junk yard good option. With connector and Fast-On terminals, and bracket for easy install.

I purchased 8 for $35 shipped. I will do more tests. I used similar DG508 for a COP ignition, but it was angled. The DG511 is straight and does not require cutting and mods. The electrical characteristics were excellent.
Click to expand...

Are you saying this DG511 will work with the motoplat ignition ? I am ignorant of most things electrical...
Did you research the Motoplat or were you already familiar ?
 
I did enough research to find many trying to sell used coils for $100 and more, is ridiculous. Does the bike have a CDI or points ignition? It should work for either. If you have a good Ohm meter for low Ohms measurement, check resistance.
 
Not sure what you have. Motoplat seems to have all sorts of stuff, might even have some diodes or circuit inside. I might be all wrong .... don't have any idea about what is happening at flywheel gen/trigger and coil. I would have to be there. Seems lots of issues.
 
CDI dumps a charged capacitor into coil, so it should work. I typically use scope and other equipment to verify what is happening and appraise situations. I have made ground up ignitions for many engines just for fun.
 
I have seen references to these being A/C and possibilty of damaging the cdi if the wrong coil is used. I dont know enough to parse it all out .
 
Have you tried digging into it just a bit? Exacto knife, etc? Get enough "purchase" to fasten something to it?
 
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