Moparman1966 Posted March 20 Share Posted March 20 Good evening, Recently picked up a F12 that has been sleeping for 40 years. I have a weak/intermittent spark issue. What I've done so far is file/clean points, swapped condensers from a parts unit, same results. Magnet seems good and strong. I can see the points sparking sporadically when I spin it over with a drill on the bench, mainly at higher speeds. Any thoughts?! Thanks! Paul Quote Link to comment Share on other sites More sharing options...
Diesel Doctor Posted March 20 Share Posted March 20 11 hours ago, Moparman1966 said: Good evening, Recently picked up a F12 that has been sleeping for 40 years. I have a weak/intermittent spark issue. What I've done so far is file/clean points, swapped condensers from a parts unit, same results. Magnet seems good and strong. I can see the points sparking sporadically when I spin it over with a drill on the bench, mainly at higher speeds. Any thoughts?! Thanks! Paul The next step would probably be a coil. Quote Link to comment Share on other sites More sharing options...
rustred Posted March 20 Share Posted March 20 18 hours ago, Moparman1966 said: Good evening, Recently picked up a F12 that has been sleeping for 40 years. I have a weak/intermittent spark issue. What I've done so far is file/clean points, swapped condensers from a parts unit, same results. Magnet seems good and strong. I can see the points sparking sporadically when I spin it over with a drill on the bench, mainly at higher speeds. Any thoughts?! Thanks! Paul and what is happening turning it over slow so the impuse does its job? just flip it over by hand or with a vise grip on the drive lug. Quote Link to comment Share on other sites More sharing options...
rustred Posted March 20 Share Posted March 20 1 minute ago, rustred said: and what is happening turning it over slow so the impuse does its job? just flip it over by hand or with a vise grip on the drive lug. i am asking because they do not turn that fast on the tractor. get a plug and stick it in the vise set the mag on and give it a flip. it should have a snap and blue spark jump. Quote Link to comment Share on other sites More sharing options...
snoshoe Posted March 20 Share Posted March 20 Yes use a plug to test. There is a safety gap inside mag where spark will jump instead of end of wire if gap to big. Might also check that gap that wire hasn't been bent. Quote Link to comment Share on other sites More sharing options...
Binderoid Posted March 20 Share Posted March 20 Before you spend money on it (not that a coil is expensive), take it all apart and get it squeaky clean. Oily primary wire and rough contacts will limit the amps available to build the primary field. Remove the contacts and carefully dress on an oil stone so they are smooth, and meet squarely. I’d replace the primary wire entirely, don’t even try to clean it. While you have the magnet off, see if it will stick to the side of the radiator. If not, it needs to be recharged. Leave the magnet stuck to something the whole time you are working on the mag, to guard it’s magnetism. Clean the distributor rotor with lacquer thinner so it is clean and dry; leaking voltage through a dirty rotor will cause a kick-back if the impulse coupling fails to latch for some reason. If all these maintenance items fail, then replace the coil. Go through the impulse mechanism as well, make sure the pawl is free and not gummed up. Quote Link to comment Share on other sites More sharing options...
Diesel Doctor Posted March 21 Share Posted March 21 Reminds me of Zack. The mechanic who had polio and skidded himself around the IH shop on a reinforced bottom of a chair. He could fix anything. He would take his stubby greasy fingers and tear anything apart. He would probably polish the points with a match book striker. He would put it in the vice and snap the impulse while having a wire come out of it. If it shot a good blue spark, it was fixed. If it hit him and he jumped, then he knew it was fixed. If it didn't work, he went deeper. Until things got fixed. RIP Zack! 1 Quote Link to comment Share on other sites More sharing options...
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