Re: 1975 Johnson 135 No spark starboard side

[roj115]

I had a ’74 Johnson 115 for 40 years and did all the maintenance on it so am very familiar with those motors.

Do the easy things first and don’t assume anything. I learned this the hard way one time changing out almost every component in the ignition system to troubleshoot a no spark on one cylinder only to find out that the spark plug that LOOKED perfectly good and I assumed worked was actually dead. All kinds of time and effort and money spent needlessly because of an untested assumption. Du-oh!!! 😳

Start at the bottom end of the ignition system and work your way up eliminating components as you go. You may have one thing wrong with one cylinder and another thing wrong with the other. Don’t assume ANYTHING works based on looks. Test everything to verify that it works or doesn’t work.

Eliminate problems in this order:

Spark plugs
Spark plug wires
Coils
Power Pack
Stater/timer unit.

To eliminate problems with the spark plugs, wires and coils, swap the components with the other cylinders that you know are working or swap in tested and known (NOT ASSUMED) good spares.

My experience with those power packs is that they either work or don’t work and very seldom fail partially so my guess is that the problem(s) lies/lie in the components downstream of the power pack. Your testing will either bear this out or prove it wrong.

Good luck and let us know what you find out.