1939 WC

Today is the first warm day in northern Minnesota and I took the tractor down the road for the first time since the rebuild.  After it got somewhat warmed up, it started not really missing but acting like it was shutting down.  It would be okay if it wasn't pulling or if it was going down hill.  By the time I got four miles down the road, it would shut down every 200 feet, I'd let it cool off and then go another 200 feet.  After cleaning the carb and reinstalling it at my friend's shop.  We fired it up again and it worked for a while but then started shutting down after it was warm.  We reset the needle valve and air adjustment.  When it's running, it sounds very good.   I was wondering if this sounds like a coil issue.  That wasn't replaced during the overhaul.  Any ideas would be much appreciated.  Wayne

Welcome to the forum! As for the WC, I would double-check all of the ignition settings. (timing, points air gap, etc. Make sure that the grounding tab is not corroded up and causing it to ground the points occasionally(if it's a magneto). Could also be a condenser going south on you. I would clean everything really well, including taking the mag apart and (carefully!) cleaning all of the connections to the coil. If that doesn't fix it, change the condenser. If still acting up, may be the coil. Just double check the fuel system first. Make sure there is nothing in the tank that could float over the fuel outlet and cause it to starve for fuel. That has happenned to several, and causes intermittent stalling.

To answer all of your questions and to clarify, we didn't actually do an engine rebuild on this tractor as the mechanic determined it wasn't necessary because compression was good and visual inspection and so forth.  It is the original six volt electrical system separate from the magneto.  I don't even know where the points are on this mag.  I have the mag off and plan on taking it to our local auto electric shop which is an old establishment that has done a lot with farm tractors.  Do any of you think they could test all of this stuff out?  I also plan on putting in a new carb kit.  Wayne 

Get the mag checked out. Tell the guy just how the engine is acting after warming up. I'll bet money on the coil or the condenser.

Dave, I think you're a little mixed up there. All fuel tanks will have water condense in them. Any fuel you buy may have water in it. If you run regular gas the water can build up in the tank to a point the engine won't run. It can also start rusting the inside of the tank. However , if you use gas with 10% ethanol, it will absorb the water and carry it through your system to be burned off as it is absorbed. This keeps water from building up in your tank and also keeps you your whole fuel system cleaner. 

Bad SP i meant CTucker