C90 2 Stroke inginition Coil Question

[whaler82]

I recently had to replace one of 3 ignition coils. It was non functional; no spark. Motor became rough running and so on. Again I replaced it and on I went -problem solved.

My question is do ignition coils diminished in effectiveness over time or do they either work or not work? I dont know how old the other two coils are. Should I replace those too ? Motor is a 1997. I though maybe at one point I replaced all three 10-12 years ago. But I could be wrong.

[boscoe99]

Coils can fail in a number of way.

There can be an open circuit with renders it useless. There can be a short to ground that will render it useless. There can be a build up of internal resistance which might diminish the performance.

Insulation gets old and brittle. Cracks in insulation occur. Moisture gets into the cracked insulation.

Stuff just wears out.

Ignition coils -- What every tech needs to know - Automotive Service Professional

I would say if the motor is running fine with just one of the three coils replaced then just keep on running it.

[whaler82]

Coils can fail in a number of way.

There can be an open circuit with renders it useless. There can be a short to ground that will render it useless. There can be a build up of internal resistance which might diminish the performance.

Insulation gets old and brittle. Cracks in insulation occur. Moisture gets into the cracked insulation.

Stuff just wears out.

Ignition coils -- What every tech needs to know - Automotive Service Professional

I would say if the motor is running fine with just one of the three coils replaced then just keep on running it.

Did a little research in my files. Spark plug caps replaced in 2003. Not the coils. That means other two coil are original.

[boscoe99]

Yep. There is more than just the coils. There is the spark plug cap, the spark plug itself and the condition of the coil ground wire to ground connection.