76 Johnson 35hp weak spark

Borg

Recruit
Joined
Jul 30, 2011
Messages
1
Motor:
1976 35hp electric start

Problem:
Weak spark on bottom cylinder. Almost unnoticeable with a spark test light. Top Cylinder works just fine.

Diagnostic and corrective action to date:
Replaced both coils, tested leads going to coil with a 12v. test light- both leads flash when engine is cranked over. When leads to the coils are switched to opposite coils, the weak spark switches to the other cylinder. Removed the flywheel and checked the gap on points to .020". Checked to make sure that the flywheel is not rubbing the stator and pickup coils. Move/switched the condensers to the opposite points, yet no change. The weak spark remains on the bottom cylinder lead. Points are clean.

I would appreciate any help. I have just about ran out of ideas except to replace the points/condenser and replace the wiring harness from the flywheel to the coil.
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: 76 Johnson 35hp weak spark

If the weak spark moves with the coil swap, you have a weak coil.
 
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