RE: Another Question about the OS 40 LA
No it's not normal... you can live with it but it will fill your engine compartment with oil goo....
take off your muffler and you can make two things:
cut out a cardboard gasket from light cardboard about 1/32or 1/64 inch (any thin box will do) and make all the holes in its proper place and put the gasket between the engine and the muffler
or get a silicone based (permatex or similar) tube and use it to form a gasket by spreading a thin film of silicone around the muffler, be careful not to put too much or it could be ingested by the engine