Oil fumes in the crankcase are common. Excessive oil fumes can be an indication of a broken or worn piston ring.
It sounds like there is too much pressure in the crank case, causing oil fumes to be cycled through the breather. High pressure in the crank case is caused by worn cylinder bores, allowing 'blow by'.
There is no oil in the crank case,,you use mixed gas and oil that's what lubes the crank bearings and piston rings.
What oil
PW 80 is a 2 stroke. It does not have oil in the crank case. I think you mean transmission oil. I use 10w40 engine oil in mine and it works great.
That depends on your moped. Most mopeds madein the 80's are two stroke engines. Which do not use oil in the crank case. the oil is mixed in with the fuel.
your crank case does not take oil at all. your transmission however will take usually 1 to 1.5 quarts of approved transmission oil.
By removing the plug at the bottom of the oil pan and letting the oil out.
It is inside the crank-case.
no oil goes in the crank case, it uses lubrication from the 2cycle oil injected into the fuel that runs through the crank area
1 quart
None
If the engine were to backfire for whatever reason and the pcv valve is stuck open, the backfire could carry into the crank case and ignite the crank case fumes. I have seen valve covers blown off an engine from this situation.