Jubilee died...beyond basic troubleshooting

Sure you are on the compression stroke of #1 cylinder?..

I use my thumb over the plug hole wile cranking it in bursts to determone when its coming up to TDC on the compression stroke...then the distributor can be put in ,in the proper position..

You can set the timing with a test lamp by leaving it at TDC and hooking the lamp to the negative coil wire ,the points side,and to ground--slowly turn the distributor until the lamp just comes on,then tighten it there--that will be close enough to get it to start and then it can be timed with a timing light (or by ear!) after its warmed up..

If it still fails to run after doing that and it has spark (if its backfiring out of the carb I'd say yes!),then maybe the plug wires aren't in the right firing order--or maybe the timing gears have let the valve timing jump..

I dont know if these tractors used a fiber composition on the cam gear or not,many inline car and truck engines do and it can fail after a long time..also if the distributor uses a roll pin to hold the drive gear on it,check to see that hasn't been sheared and let the gear slip..

Once you had spark across all 4 wires, did you try to start it? Or did you dive right into the timing?

I recently fought a similar battle with my jubilee. What began last fall as bad points there were not opening to the right gap, progressed to a bad coil this spring. In the process of trying to fix that, I caused a new problem by grounding out the nut at the distributor. This was a maddening process to say the least.

If you dove right into the timing, then I wonder if you fixed your original problem, only to create a new problem to deal with. I suspected timing in my case too, but abandoned any efforts to adjust the timing for several reasons. First, my tractor was running, then died suddenly. How could that be timing? Either the timing is right or it isn't. It doesn't go from right to wrong all of a sudden. On top of that, the marks on the flywheel and the position of the rotor didn't make any sense. When the rotor was pointing at cyl #1, I couldn't even see the timing marks. They only appeared when the rotor turned 180 degrees. How could my tractor run if the timing was that far off?

I know that my jubilee had an engine rebuilt at some point in its past. I blamed the timing mark problem on the possibility that the flywheel was not reinstalled in the correct position. Having never seen this tractor ripped open, I have no idea whether that is even plausible. But I decided to put my faith in whoever timed the thing before me, and didn't adjust the timing at all.

I am glad I didn't. Once I really solved all of my ignition problems, the jubilee started right up. If you dove right into timing, you might want to try returning the timing to where it was (or as close as you can remember).