farmall cub electrical problem

[dan moore]

i have a 49 farmall cub. you can take a plug out, check the fire and if you have fire it will start. it runs better than a cadillac. may run 20 seconds or 2 minutes and 20 seconds. when it quits, you have no fire. have replaced ignition switch, coil, points and condenser, coil wire, and insulator where wire goes in dist for points.have also inspected wiring. you can go anytime and check fire, if it is there it runs for short peroid of time... when you have no fire, i am getting power to the coil. tractor was rebuilt a few years ago and has not been ran many hours since. at that time dist cap, rotary button, etc were all replaced... any ideas would be appreciated.. have about lost my religion over this. am convinced it is something simple, but i can not see the forest for the trees!

 

[lhfarm]

Welcome to TBN! Even though you have replaced the coil, I'd have it tested, just to be sure. I have had "new" parts be defective out of the box. When you don't have spark at the plugs, do the points "arc" when you open'close them with a screwdriver? What do you do to get spark again - wait? How long? Crank the engine or do anything?

I'd also post at FarmallCub.Com - Home or one of the other Cub sites. Hang in there. Great little tractor and lots of fun when they run!

 

[dangier_VA]

Dan,
You say you have checked the wiring. Did you take it apart and check each run (and good grounds)? How old is the wiring? If old or original, I might replace it. Might have a broken wire that makes contact momentarily. I would also clean each ground down to shiny metal.
Let us know.
David

 

[jimmysisson]

You have your point gap set correct, right? A four-lobe dist is pretty simple but your coil needs the soak time so the gap still needs to be right. Bad condensor? Or coil.
Jim

 

[Soundguy]

bad condensor or bad ignition switch is my gues.

easy to test both, one with a jumper wire, other with an ohm meter.

soundguy

 

[TrippleT]

Take a test light and when it dies check the wire to the coil. If there is not fire there go backward to the switch. If there is fire at all times to the coil, and everything is working you might use a coil tester. And check again the points and the condenser.

 

[Soundguy]

points and an engine are the best coil tester there is

soundguy

 

[ccw]

ive got a 1974 international cub. it'll turn over but wont start. changed coil and condenser. frustrated.

 

[Soundguy]

have you checked spark?

 

[grainger12002]

take the ign. switch out of the loop til u find the problem, power the coil direct, rmember it was pos ground ,if its still 6 volt-

keep us posted