1976 9.9hp Johnson Misfiring while on Throttle(solved)

[Mr. Bwok]

My 1976 Johnson 9.9hp is starting, idling perfect on both cylinders. however when I go to give it any type of throttle it starts to misfire and shut down the top cylinder. Any ideas?

 

[Daviet]

Re: 1976 9.9hp Johnson Misfiring while on Throttle

Re: 1976 9.9hp Johnson Misfiring while on Throttle

You could try swapping the coils and see if the problem moves ton the other cylinder? Then you know you have a bad coil.

 

[Mr. Bwok]

Re: 1976 9.9hp Johnson Misfiring while on Throttle (SOLVED!)

Re: 1976 9.9hp Johnson Misfiring while on Throttle (SOLVED!)

I found the culprit. I had a bad connection on the stator plate. The wire harness was grounding somewhere when throttle in wide open position. I took some flat 14 ga pvc insulated trailer wire with two wires inside, cut to length. Spliced into exisiting connectors, so could still quick connect to coils and rewired under flywheel making sure I had the top and bottom cylinders hooked up properly, redid the ground wire. Put all back together and no issues with misfire, now I have a 400 RPM dropoff at WOT that is driving me nuts.