2000 Catalina 310, Hull #18 has only 216 hours on the engine. I'm going through 10 micron secondary filters like mad. There's nothing in the bowl on the 30 micron primary Racor filter so I assume I've got a gunk problem in the fuel tank. I'd prefer not to remove the tank and I know I can empty it 90% with the fuel pump. Does anyone have a practical idea regarding how to completely drain, inspect & clean the tank in place ??