15 johnson 1975 electric start spark quandry..

[kbait]

This is the one w/a trickle charge, and points ('74-'76). I have a spark tester, and no/very weak fire on lower cylinder. Disabled kill switch connectors, and inspected the rest of the wires(2) to the connection w/each coil and point set.

I am sure coils/condensers/points are functioning for the lower and upper cylinders.

Here's my headscratcher. If I disconnect the connector between the stator and top coil and test, strong spark to bottom cylinder. If I then reconnect that one, and just unplug the connector between the stator and the bottom coil and test, NO spark to top cylinder (or bottom, of course).

Both coils connected: Strong spark to top, and VERY little/none at bottom.
Top coil connected only: No spark at all.
Bottom coil connected only: Strong spark to bottom.

Does anyone have a clue on this? I understand point ignitions, but not so much when it has electric start and charging coils. It seems like there's electrical feedback/bleed off or something, but I just can't see where. Thanks ever so much for your consideration!

 

[kbait]

Re: 15 johnson 1975 electric start spark quandry..

I must amend a bit. I used the above motor tonight, and it indeed runs on only the upper cyl at slow speed. When I throttle up, it immediatly runs on both cyl's perfectly. There is something up w/ignition I still cannot see. Please help!! ps. I did throttle up on my spark tester test earlier. It still had the same symptoms. Thanks again...