I would also think about checking your oil seperator box (breather box) that is connected to the s-shaped hose that houses the flame trap filter.

When I checked mine I had to replace all the hoses that makes up the flame trap system. When I pulled the s-shaped hose from the top of the breather box it was totally plugged up-and it wasn't sludge it was hard as a rock. When I tried to remove the box from the engine block the lip that fits down into the oil drain hose cracked and broke-I was careful but it was brittle. Had to replace it.

And if you need to replace your breather box definitely go with genuine parts (bought mine from Tasca-$35 compared to local dealer $56!!!) I learned quickly from reading numerous posts here on the BB that non-genuine parts when dealing with the breather box is a no no!