I was running my 20B and noticed a high pitch whine. My first thought was an alternator bearing. Course its a bit hard to all with all the exhaust noise....anyway, upon closer inspection it is the metering oil pump making the noise. I'm running the adaptor from Richard Shon (I think thats the right spelling) for an outside oil source. It seems to be working fine, but the noise bothers me. Anyone else run across this?