1972 Johnson 25

[parratt1]

Went through this motor 2 years ago. Just took it out for the first time yesterday and it ran great. Purred like a kitten. But, on a 16ft Jon, I could only go 5.5 mph. This morning that I took the top off and checked and I have no spark to the top cylinder. A buddy of mine who is an auto mechanic had me swap the coils and retry and I still had only spark on the bottom cylinder. He then had me swap the capacitors and same thing only spark on the bottom cylinder. I changed out the top spark plug wire as well with a new one and still no spark on the top cylinder. What can possibly be causing this? I think points are the only thing left. I've gotta be missing something.

 

[Roberthill]

You've went this far and you say only points left maybe you answered your own question , I think I would try it .

 

[oldboat1]

Dress the points with a match cover or business card and acetone or lacquer thinner. Reset at .020. You can test by seating the flywheel in place, and flipping it quickly by hand (clockwise) -- torque it down when you know you have spark.

Use an adjustable spark tester.

 

[oldboat1]

(plugs out for hands-on testing, of course. Probably know that, but better to be insulting than get somebody hurt.... In the same light, keep the spark tester away from the plug holes.)

hope you get it solved.

 

[parratt1]

I've never messed with points before. Just need a set of standard feeler gauges or do I need the brass ones?

 

[AlTn]

standard is fine...clean the end of the feeler gauge with acetone, carb cleaner, etc. to remove any oil before using