Vilhuer

Small ball bearing #40 keeps oil from flowing back down from inside head oil feeds. Spring #41 keeps it tight and o-ring #43 seals hole made into head for ball and spring. O-ring is on #42 which is kept in place by threaded pin #44.

PET lists only one set of parts but I could swear both heads have same setup. No point really to have just one head retain oil in it for next startup. On drivers side oil feed comes up at about same fore aft position where oil filter is IIRR and thats where these parts should be too. Look for end off #44 sticking out from head casting on outside at exhaust side and top end of #42 inside head below exhaust cam position. There is thread on top of #42 to assist its removal once #44 is take out of the way.

AO

I think I found the check valve. It's in the lower left corner of my post #16. But I don't see how to remove it - it's not obvious. I'll consult manual.

Ed Taylor

Andrew, There is an allen head set screw on the exhaust face of the head that secures it.

Edit: found this from Tony, Hope it helps.
http://members.rennlist.com/v1uhoh/oilcheck.htm

AO

Thanks Ed... I'll check it out.

Hilton

Just remembered reading this at some point..

http://members.rennlist.com/v1uhoh/oilcheck.htm

AO

Thanks. I found the set screw - it was covered in gunk.

Vilhuer

http://members.rennlist.com/v1uhoh/nasty.htm