Have you replaced the condensor, plug and set the gap on the points? If one of these are bad it will not run.
I have changed out the condenser, coil, and points with new parts the seller gave me. I know the point is not gapped 100% correctly, as I have not had time to get a set of feeler gauges. It is set close enough to at least run rough.
I don't think it's a problem with the engine from what you've described. I think it's electrical or in the ignition system somewhere. Hopefully the place you take it to is honest and doesn't take you for a ride. I'm still thinking it might be a ignition switch the failure of these is very common. I would look up Brian Hildreth on here and message him. He will be able to tell you how to trouble shoot the switch and can get you a new one.
I'll take the tractor to one of 2 very reputable shops. I have dealt with both and had very good experiences
I feel good about the switch. With the switch in the off position, no voltage is going to the coil. With the switch in the run position, I get 12+ volts to the pos. side of the coil.
The reason I'm thinking the engine, is because the seller used starting fluid to get the engine gunning (not sure how many times). I personally know a lot of farmers that do this and are always having problems with their engines (I know this is kind of apple and oranges). Not knowing what sound the engine made when it quit running under its own power I can not rule the engine out 100%. I'm not sure if he burnt a valve or blew out the top ring, and because of this the piston is not making compression.
I have done some research and have read that others have had the same issue as I am having, and it turned out to be the key to the crankshaft and the flywheel sheared. This would put the lobe the sets the point out of time.
I do get a spark jumping from the spark plug to the block of the engine. I figured it the piston is blown I'll use some brake cleaner to start it, that did not help. I could take the plug out and crank the engine over and see a mist of brake cleaner coming out of the plug hole.
I know this got long winded, thanks for putting up with me on this issue. I'm sure I missed something, ask and I'll fill in the blanks.