You had asked about installing umbrella seals to cure a plug fouling condition on your Farmall H. You gave extra info about compression, etc. that helped me to understand the situation, here is my response:Thanks for giving the extra information - some of us need to see the "whole picture" in order to make a suggestion... Do you run the tractor only for short periods of time? Do you have a working thermostat (at least 180 degrees F) installed so the engine comes up to temperature in a short period of time? What do the fouled plugs look like? If they are black, you have a fuel/air problem - running rich or just not run long enough to warm up. Have you tried hotter plugs? I believe Champion D19 are the standard, D21 will be hotter and less prone to foul. Our 544 fouls the D19 in a day (fresh overhaul) but the D21's never a problem - we only run for short periods of time... Some say the champion plugs are the problem and go to Autolite 3116 (I think that's the right number). I hope this helps you out!
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