Ignition Coil

[Themanofsteel]

I have a 85hp Force (1988). The ignition coil stopped working about 2 years ago. I bought a USED one identical and it had been working fine but stopped working now too. I tested it throughly & it's not working. I'm going to buy another one but can anyone possibly tell me what would cause the same coil to go out?

FYI
I did have a wire break off in mid-drive causing me to loose power. I stripped it and reconnected it on the water and if ran full power. That happened twice to 2 different wires because they are old and brittle. Those wire happen to power the First Ignition Coil. They were the wires coming from the Magneto.

 

[jerryjerry05]

Same coil going bad?
Possible the trigger is sending too much voltage to the coil?
Bad connections?

​Have to ask: you try swapping the coils around?

 

[Themanofsteel]

Yes I swapped #1 with 2 & 3 to test to make sure it was the coil and not the CDI or a connection. The other coils spark fine.
Concerning connections, I as stated in my post, on 2 occasions wires coming from the magneto broke off prior to the coil going out. I have since repaired all wire connections.

The wires broke because of vibration and it seems like my engine is vibrating more than I previously remember. Or maybe I just never really paid attention to that before.

What is the trigger? And how can I test the voltage coming from it.

 

[Jiggz]

It could just be plain coincidence. When the new coil arrives, and I mean brand new coil, place it on #1.

 

[Themanofsteel]

Jiggz I was actually planning on putting the new coil on 2 or 3. If something is damaging the coil on 1 I don't want it to damage the new one.

Should I still put on 1?

 

[jerryjerry05]

Under the flywheel is the stator and in the center of that is the trigger.
Check the trigger resistance, trigger wire sets read approximately 50 ohms between the wire sets (DVA-5V or more), and open to engine ground.
​Had a serious backfire/crossfire and finaly chased it down to a trigger shorted between two sets of wires.
Somehow it was getting 25v+ instead of the 5

Get the specs for the trigger you have.
OEM might be different than a replacement.??

 

[Themanofsteel]

jerryjerry05 I assume I need to remove the flywheel right.

You mention about backfire. I've had some pretty loud backfires recently when starting the engine.

 

[Jiggz]

The reason I mentioned coincidence is due to the fact the previous replacement was also a used part. Now if you put in a brand new part, for sure if it dies down, you can clearly conclude there is something that is killing the coil and not just a mere coincidence from a used part. The truth, if you placed an old part (one from #2 or #3), then there is that suspicion that it could be because it was an old or used part.

Besides, either the new replacement part or an old existing part getting damaged by #1 cylinder again will require you to get another replacement part, except that if you used a new one it'll clearly indicate there is a problem with #1.

 

[Themanofsteel]

Jiggz makes sense. Just didn't want to ruin a brand new one but I understand.

 

[jerryjerry05]

No need to remove the flywheel to test.
The wires are thin and they have tags on each one.
Make sure they are remarked if the tag falls off and the connector replaced.
The wire at the connector breaks under the shrinkwrap, that's why I replace them ALL.

Lots of backfiring?? Sucking air somewhere??
​Start it and spray starting fluid around the intake side of the motor.
​Gasket on the port covers? carb gasket? loose carbs?

 

[Themanofsteel]

jerryjerry05. How do I test resistance with a multimeter. Where do I place the wires coming from the multimeter?