1974 15hp twin cylinder problems.


New member
I am only running on one cylinder and I’m hoping someone can just verify what I believe is already happening.

The engine idles a little rough, however, when putting into forward the engine does not rev and almost just stays stagnant. Every so often the engine will roar to life and nearly jump out of my test tank.

I figured out that cylinder one is not firing when running since I pulled the wire and it didn’t die or make a different. Cylinder two will kill the engine and also give me a nice little shock. I have swapped coils to test that theory and it is always cylinder one.

My my thought is that the solid state unit or cdi under the flywheel is only good on one side. And the other is almost completely shot. Can anyone confirm my thoughts?

Also, are these repairable or do they just need to be replaced?