87 Wellcraft Scarab I. This issue has been going on for years. The engine will run fine for at least 20 minutes or even for the day. I will be crusing at a steady speed (40MPH) then it will drop 5 MPH and will have minimal exceleration. Give it 5 minutes and the power comes back but can fade again. If I slow down it clears quicker. It's seems to happen once I get down to half a tank or below? I have replaced leaking fuel tank (60 gal), filler tube, breather tube, fuel lines, fuel pumps, rebuilt and cleaned carbs a few times, fuel filter cleaned, plugs look ok, new reed valves. I'm thinking about installing a remote fuel pressure gage and water fuel seperator. Could it be a main seal?
