one thing that wil definately, without doubt, also make you vent oil is if you have put too much in in the first place! Its something maybe even the previous owner did?
It never hurts to change the oil, so, if you havent got a blocked crankcase or breather pipe problem ( make sure all the breather hoses are not blocked or twisted / nipped anywhere) Then it may be worth your while to drain all the oil out from both the tank and the sump and oil filter.............
Then refill WITH NEW oil very carefully measuring the correct amount as stated in the manuel.After first putting in a new filter of course...
Just looking in the tank may not tell you if its been overfilled....it happens. But draining the old out will
( if you measure that!)
Keep us posted.
