1957 OMC 35hp Electrical Problem

[bruceb]

OK, so just to set this up, I'm not Bruce Buck, and this is quite possibly a different problem....
The motor has the magneto system, electric start, no generator. Has a solenoid mounted in the engine rather than the separate relay box, as was originally stock. Has a separate elec circuit through a panel with no key switch.
This motor has run just fine ( with a few other issues !) for five years now. Recently, and not coinciding with any other changes, it's had a live spark when the cowl is touched. I found one spot where it was arcing across from block to cowl, so eliminated that. Found another and haven't cleaned that up as I want to find the reason why there's a live current coming from the coils/armature plate. Have inspected all the possible areas- plug wires, loose wires on coils possibly rubbing on underside of flywheel, etc.
Is it possible that I have a coil that has reversed polarity, and how does it get "reversed" ? Right now it's acting up and running on one cylander. I know which cylander as it's wet and the other is dry. Changed the suspected coil last week but the symptom is still there.
Any guesses/places to start ?
Thanks, bruceb

[Brian]

Have you replaced the spark plug leads from the coils to the plugs? They can look ok but under load, short to the engine block or the magneto plate in a couple different places. 50 years is a long time for an insulator.

If anything else was shorting, it shouldn't have enough current to do much but ground out the cylinder. My main engine now is a '58,'59', '62 franken-rude-son, using parts from 5 motors. Got another motor to build out of the pile waiting on the back burner. Good luck!

[bruceb]

Thanks for the response, Brian. I only have the last 5 years or so on this motor, and I haven't changed the plug wires in that time. I had the armature plate off and inspected the wires from the lower side- they had a little white chafing where they routed past posts, but otherwise appeared OK. I've wrapped the 90 degree boots at the plugs with elec tape to eliminate that as a possible contact location but hasn't eliminated it. I have just one parts motor for this baby, ha ha, and I'll take that apart to see if there's a wire to swap across and test. The new coil I've purchased has fewer plates on the magnets as the older one. Should I be using identical coils ?
Thanks again....
bruceb