Force 1986, A 125 intermittent ignition problem

seamoors

Cadet
Joined
Aug 27, 2008
Messages
16
Hello,
Been troubleshooting above motor for spark problem on top cylinder; thought i narrowed it down to switch box because the problem seemed to follow the wire from the switch box to the other coil when swapped. Just to be sure, i completely swapped both switch boxes and.... now no spark problem. Put everything back together as normal and.... no problem, runs great.

I hate an intermittent problem as you never know when it's going to pop up again, but it will pop up again.

My question is, in your experience, did i correct a problem (like a bad ground or a push plug that wasn't contacting perfectly) or is there a part in this ignition system that is notorious for causing an intermittent spark problem (trigger, stator, switch box).

the chain of events is as follows:
The top spark showed as a dull, orange glow on the in-line spark viewer. Rest had strong spark (although when second from top wire was disconnected, made no difference in the way engine ran - strange).
When i swapped coils, the dull glow moved to the other coil (eliminates coil & wire as problem).
When I swapped just the trigger plugs on both switch boxes (forgetting to swap the stator wire plugs), the problem spark stayed with the original switch box. When I realized the stator wire plugs needed to be swapped (or do they?), the problem seemed to disappear. Baffled, I put everything back to original. Motor now runs great, strong spark on all plugs.

sorry for wordy post, and thanks in advance for any input.

colin
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: Force 1986, A 125 intermittent ignition problem

I had a similar intermittent ignition problem on my 1988 125HP motor. Turned out to be a broken wire on one of the lugs on the terminal block by the coils/CD units. Each lug has a piece of black shrink wrap insulation that covers the connection between the lug and the wire. The wire had broken under the shrink wrap and was not visible. Even when you pulled gently on the wire, the shrink wrap prevented the wire from coming out. I did notice that the wire that was broken was much more flexible at that point than the other wires. Also, check the ground wires from each coil to the mounting plate, and ground from the mounting plate to the block.
 
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