I have an 02 outback with the carbed indmar assault 310.

Heres the back story. Last fall on the last day of the season I began having trouble getting my boat started. Zeroed in on the oil pressure monitor switch. I bypassed the switch to get it running to winterize it. Put stabil in tank and ran it for about a half hour to get it thru the fuel lines. Replaced the switch this spring, and the old girl fired right up. Warmed it up and took it for a few fast laps around the lake. When I put it into neutral to come back into the dock it died out on me. Was able to finally get it started but would not stay running at slower speeds or neutral.

So I pulled the boat out of the water and started checking things out again. Took the fuel pump off and a bunch of watery residue came out of the pump. Flushed the fuel pump with fresh fuel and replaced it. I also flushed the fuel filter. Tried starting it again but would not stay running.

Brought it into the shop and of course the carb was all messed up, but they also found a bunch of residue in my fuel. Not sure how this happened. I run 91 octane and have screens on my fuel cans. I assume its a poly tank, so the tank would not be caroding. Not sure if somebody vandalized my boat and put something in the tank or what.

Do I have to remove the fuel tank to clean it out or is there a way to flush the tank without removing it.

Any other suggestions or info would be greatly appreciated.