by SteveMRC » 22 Jun 2006 18:41
Morini V Twins don't have a normal paper oil filter, they have a gauze filter under the oval shaped plate on the right hand side just above the oil drain plug.
Wash it with petrol, dry it and put it back in.
The oval cover has a cut out in the back, the thick end goes at the top when you replace it. You will see what I mean when you look.
My 478cc engine takes 3 litres, not sure about the 501.
Hope this helps
Steve