Spark keeps fouling but no clue why

Yes it can. Does the spark plug look wet and oily, or does it look black and sooty? Wet and oily can be from a worn or broken oil scraper ring, or from bad seals on the valve stem.

Hi Josh:
I'd put fresh plugs in it and drive it for a week, then check the plugs.
Sometimes you will get high compression readings that are not valid because the rings are soaked in oil so they think they are sealed when they are not.
With the engine off, you could try removing the oil filler cap when the engine is hot, then restart it. A little vapour is OK, a lot indicates bad valve guides, head gasket,or ring blowby.
Also, try checking inside the exhaust tailpipe. If it is oily sooty it is also an indication of possible ring problems.
Review the maintenance history. How many miles on the engine? Could be the engine is getting tired.

No, oil is fouling from piston rings leaking a little. Clean it up or install new one. Pull and check after a few days . if its real oily again then you have a problem if not your ok.
this is really a normal condition on old plugs not changed. you only have one cyl doing it so you should be ok

I am assuming it is oil fouled rather than fuel fouled. Oil fouling is usually due to valve stem seal leakage. Most engines have the oil return on the cylinder head at the rear. When the engine is shut off, some oil pools at the rear of the head. If the valve guide seals are worn, then the oil will leak around the stem of the #4 valve and eventually foul the plug. If there are no real issues with the engine other than this one, it is usually best to keep a clean plug or two available and swap out the plug periodically when fouling is detected. Then clean the fouled one and keep for reuse later. If it is happening too often, getting the cylinder head reconditioned is a good idea.

remove spark plug wire than remove plug and look at the plug end should be clean --black build up =carbon///wet oily =burning oil usually shows up with a blue cloud oil getting into cylinder

If the black deposits on the sparkplug are dry and fluffy then your problem will more than likely be a blocked or restricted airfilter. Your airfilter should be the sponge type, wash it in a soap water solution, dry it thoroughly then apply clean engine oil to the filter, squeeze it through then squeeze out the excess in a dry clean cloth. This will leave a fine residue of oil to trap any particles of dust. A heavy residue of oil in the filter will cause the problems you arte experiencing.
If the black deposits are wet and oily then either the sump is overfilled or the piston rings and cylinder are worn.

Wath is the saund- hawe no spark or ...?

its not totally abnormal to have gas in oil, fouled plug could have contributed to this as with a fouled plug some gas is not being combusted, however if the fouled plug was replaced and veh is running corrected i wouldnt worry bout it good luck billy

Change your spark plug
If the fuel oil mixture is too oily it will foul the spark plug and no cleaning will get it right.
If there is a lot of oil in the crankcase it may foul the new spark plug so another new one is needed