1973 Evinrude 25h.p. Spark issue

[trucktech]

Hi, I'm having a problem with my model 25353a Evinrude 25 h.p.(1973). It always runs great, unless I slow to an idle for a few minutes. Then I lose spark to the lower cylinder (confirmed by spark test). Sometimes by accelerating, it will fire again and run fine. Sometimes not. I have replaced the points and condensors, but the problem remains. Is there such a thing as a weak coil that could cause this issue while running at low or no-load? The compression is almost equal @ 120 lbs. per cylinder. Any thoughts would be appreciated. HELP! Thanks, Rick

 

[Daviet]

Re: 1973 Evinrude 25h.p. Spark issue

Could have a weak coil. Could have a bad connection on the plug wire at the coil. Are the points set correctly, .020 gap?

 

[nwcove]

Re: 1973 Evinrude 25h.p. Spark issue

clean the points....and clean them well. ive had guys bring me motors that wont even make a try to start.....i take a strip of paper and pull it through the points and show them the black circles where the contacts touched the paper, and the black "skid marks" from pulling the paper out of the closed points. a quick and PROPER cleaning can sometimes bring a dead or cranky one back to life. jmo