Stan...I went through a lot of what you are going through when I was trying to get my Cub started after it had set up for several years (or so the owner said.)
Some things to check that might save you some time.
1. Compression...the L head engines will often turn over fine but they will have stuck valves. No engine will run without compression...a decent tester will only cost $20 or so. If you don't have compression, don't go any farther until you solve that problem.
2. If the engine has sat for a long time, I would replace the following right off the bat: points, condensor, coil, rotor, rotor cap, plug wires, and plugs. It will be $60 well spent. Once you have a good spark and compression, look at the carb.
3. Carb. again, I have found it easier to just go ahead and re-build it to make sure it is sound rather than grind away trying to start the tractor with a bad carb.
4. Make absolutely sure you have the firing order right. Firing is 1-3-4-2...remember the cylinders are numbered 1-2-3-4 from the front. This will drive you crazy if it isn't right.
Post specific problems as the arise, but your current problem is the same thing I had wrong and I had to go back to step 1 above and work my way back through before I could get mine started. Good luck...BB