david Neville higgins had this problem with the return
That was Neville, as RS above mentions. I think with such thin oil you should have metering wires in the rocker feeds. I also question synthetic oil in classic air cooled engines. When I tried it I suffered wear on the valve stems and upper guides.Didn't someone post on here a few years back about the rocker feed bolt holes being opened up a bit, and this caused too much oil to bypass back into the sump........when altering these things you need to be careful not to get carried away........