no spark 1966 mercury 350 35hp

steve mcqueen

Recruit
Joined
Jun 21, 2016
Messages
2
My Dad has a 1966 mercury 350 35hp he called and said it has no spark. I checked spark at the plug no spark. I then started to ohm test the plug wires to the coils to see if I have a short. The plug wires test good so I pulled the flywheel off to check coils. The mercury service book he has does not have the coil specs for his year they only had specs for 1984 and up the old coils tested .7 on one side and 6.47 on the plug side. The new coils test .8 ohms on one side and 9.35 ohms on the plug side so I was hoping the coils would fix it I replaced them last night still no spark. I checked the points they are gaped at .020 TDC both cylinders and they look good no miss alignment and no signs of being burnt can some one please help me. I am running out of ideas flywheel looks good motor ran 2 year ago
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
CLEAN the points. Use 400-grit wet/dry then run a business card dipped in carb cleaner/lacquer thinner/etc. through them to clean up any residue.

Also, the condensers are the weak link in those ignition systems. If all else fails, replace them. If you can't find the OEM Phelon style, it's possible to adapt an OMC condenser in its place. The OMC/BRP condensers are similar mf rating and are much more robust.
 

steve mcqueen

Recruit
Joined
Jun 21, 2016
Messages
2
Thank you so much that sounds like it could be the problem. I am on my way to try that. I will let you know when I get home.
 
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