In Reply to: Re: Stuck Valve Or Worse posted by Bruce(OR) on July 23, 2020 at 18:12:48:
This is a six-volt system. Before testing compression I removed all plugs, the throttle was open and I pressed down the clutch pedal while cranking. The engine was cold and the test made without adding oil to the cylinders, although I had added oil the day before when starting for the first time this year. The engine had been warmed up several times since then and the extra oil had burned off.
Before making this test, and in order to get the tractor started the day before, I had removed, cleaned and gapped the plugs and removed the distributor to clean and set the points. Static timing is as good as I can get it; I have ordered the timing jig from Windy Ridge Farm and Machine.
The tractor starts readily, runs a little rough at 2/3 throttle, runs better after a little warmup, starts breaking up as throttle advances. Could be a bad points condenser / capacitor, could be stuck advance weights in the distributor (went through that last year) or could be a sticking valve. I thought I had eliminated the first two but I can recheck if you think it can't be a valve.