Farmall Cub

Would a bad condenser cause a case 300 to miss and backfire? Rebuilt dist was installed and ran for 3-4 hours then started acting up. Tried a new coil but no better. Starts when it's cold but misfires within minutes of running and get's worse as it's runs. Any suggestions?

A condenser can cause it, but so can a worn distributor shaft. check for side play that may be causing the point gap to change while it is running.

Their is a new/rebuilt dis with new points and condenser in the machine. The motor was rebuilt and has not run right from the get go. Been this way for over a year. I installed the rebuilt dis because the old one had over .050 side play in the shaft and thought I had it solved. No such luck. Ran fine for two hours then started acting up again. That's why I was thinking a bad condenser.

Sounds like time to look at valve adjustment and cam timing.

That's not a bad idea. Figured they were out of play as the motor was farmed out to a rebuilder. His reply when first contacted was "it was running fine in our shop". Guess it's time to get back to basics.

Since your distributor is freshly rebuilt, it may have worn in a little and changed the point gap. I think I'd check that first. It could be a bad condenser, though.

Finally had time to work on the 300. Tried a new coil out of my cub and it still would not run right. Better but something was still wrong. Replaced the cond. and put a new coil on and it's running just fine. Sure feels good to get it back up and running again. Thanks for all the help.