I have a 1987 115 HP Mariner In-Line 6 which will run fine for about 20 minutes or so and then starts bogging down from WOT. Once this starts it will never die completely. I can back off on the throttle, idle along for a bit and then it will climb back up to WOT again, once there for just a minute or less the cycle starts over.

I've tested the stator and found one set of windings to be bad, thinking this must be the problem, I replaced the stator, (the alternator starting working again) but the running problem remains. The trigger tests good with the ohm meter, but several mechanics have told me it's still the culprit. (because the test needs to be made while the eninge it hot, which I have not done.

Do you agree the problem it with the trigger, or could the swithboxes be at fault. I've been told the swithboxes are either good or bad and will not cut in and out like this.

Any input would be appreiciated.

test for spark when warm