John Deere 3020

[FargenFarms]

I have a 1967 3020 gas tractor. I have installed an electronic ignition. I have re-built the carbeuator. It still fouls the plugs. What can I do?

[moship]

Is it fouling because of excess carbon (dry) or from oil (wet looking)? If it is from carbon running too rich or not firing completely 1) Check the plug wires to make certain they are ok. An ohm meter will work great to prove they are ok. 2) Perhaps the spark plug heat range is too cold. 3) make certain the float level is correcly set. 4) air bleeds in carb could be plug 5) Choke closed or not opening completely

[BIG DOOLEY]

Plug wire rule of thumb is usually no more that 4000 ohms per foot of wire if my memory is right.
Tom

[buickanddeere]

If the coolant temp is too low , the mixture too rich or the engine worn and burning a high ash oil. It will foul any plug. Putzing around at light load and with coolant temp under 195F is a common problem.
All too often the mixture is too rich from 35 years of dirt in the air inlet pipe work or aircleaner. A choke blade that is partly closed even through the choke knob is fully inserted is all too common.
If it's oil fouling. Use low ash SF-2 Shell Rotella T1 50 weight intended for two stroke Detroit Diesels.
Use solid core wires and Autolite 3116 plugs.