help stall issue 1970 Johnson 60HP

[jchaulk]

Hi,
I am just getting started and know very little so the learning curve may take a while. I have a model 60ESL70D / 60 HP Johnson. My problem is that the engine will only run when cold. Anyone know why or where to start trouble shooting this? Starting no problem but after running the engine for 30 min or so the engine will stall or if I turn off the engine it will not restart. I heard that the coil may be " breaking down" if so how can I test for this? Allowing the engine to sit overnight and trying to restart in the morning, no problem restarting. Is it the coil, rectifier, or stator I am a little lost.

Thanks

 

[fireman57]

Re: help stall issue 1970 Johnson 60HP

Take a timing light and a buddy the next time you go out. When it won't restart have him put the timing light on the plug wires one at a time and check for spark. If you get none on one and spark on the other I would suspect the ignition coil for that cylinder. I assume when you say it won't start you mean that it will crank but not fire. If you find one of the wires is not firing then swap the ignition coils, not just the wires, and see if the problem follows. If it does then it is an easy fix to replace the offending coil. If you see cracks on them or melted ooze replace them.

 

[jchaulk]

Re: help stall issue 1970 Johnson 60HP

Thank you ..I will give that a try an let you know how it goes.

J

 

[ddaigle]

Re: help stall issue 1970 Johnson 60HP

I have this same motor. This motor only has one coil, so you cant swap them. It is similar to an automotive system. It has an electronic box fired by points under the flywheel. Most likely your electronic box(control module) is getting hot and quitting. Still check for spark with timing light and search this forum for posts on this motor. I believe 1968- 1971 used this ignition(battery fired CD ignition). Also, make sure you have a very good battery, mine would quit after running for a while also. Th e battery had a bad cell and these ignitions require a solid 12 -13 volts to operate. The starter would crank but no fire.

 

[F_R]

Re: help stall issue 1970 Johnson 60HP

If you are still trying to run the surface gap spark plugs that came with the motor, trash them and put in Champion QL77JC4 gapped at .030". Believe me on this one, the surface gaps are useless on this motor. They cause all kinds of trouble like you are describing.