Doug Rohrer
Well Known Member
I have a new RV-9A with a rebuilt O-320 carbureted engine. I have had a persistent oil leak on the rear of the engine but could not pinpoint the source. The most noticeable oil collection seems to be around and under the new Tempest fuel pump. Oil builds up around the pump OD and on the bolt heads going up from the bottom. Everything is dry above the pump. I put a cloth "diaper" around the fuel pump held on with zip ties for a temporary test. I flew an hour today and looked up from the belly. Everything looked dry and virtually no oil on the belly. This seems to confirm oil is somehow getting through the fuel pump from the inside out. I have snugged up the screws clamping the pump together, but still see oil. Is this a common problem? Any solutions other than changing fuel pumps?