A spark plug that is unable to fire due to its oil contamination in its firing cabinet
Oil and gas mixture too rich. : o )
It's probably a mis-fire on one or more cylinders. Run a compression check on the engine, examine the sparkplugs as you do that and see if there is excessive build-up or damage and watch for oil fouling. If it's just simple build-up, and there isn't any oil fouling, just replace the plugs and wires. If it's oil fouling, you'll probably need some engine work.
Carbon Fouling of Spark PlugsUsually spark plug carbon fouling is caused by either the fuel mixture [ratio of fuel to air] is too rich [too much fuel], OR it could be that crankcase oil is getting into the combustion chambers [cylinders].Crankcase oil fouling is most often caused by either worn or broken "oil" rings on the piston, or on overhead valve engines, worn out valve-stem guides.
A two stroke engine combines the fuel and oil inside the engine. If your plugs keep fouling, that ratio is off and may be related to the choke or air intake.
If you put it in for engine oil you will have a major problem. If you put it in with the fuel then you will notice the mower smoking a lot and possibly fouling the spark plug.
Splash fouling.
Correct tuning, correct heat range plug, correct oil/gas ratio for the motor
If you own a sled that has a two-stroke engine, your plugs may be fouling due to your oil to gas ratio mixture or your carburetor is running too rich and needs to be adjusted or rebuilt.
it could be piston rings letting oil get on them it happened to mine
Probably it is burning oil. It happens if you a using a mist system of lubrication. If not, you should probably replace your piston rings. Combustion of oil causes fouling of the spark plug.
I would stay away from it. Ask yourself this, if it is supposedly good at removing oil fouling then whats stopping it from removing oil from the compressor and other places that need it.
fouling