Fuel tank clean out or removal help? And few other problems

[Tuckerboy1]

I have an 2002 mercury tracker tournament v18 special edition bass boat with a 50hp pro series engine.
Problem 1) Boat sat for a bout 8 years and has some really bad gas in it. I drained as much of it out as I could and put 5 gallons of fresh fuel in and it still was pretty bad. So I need to know if these boats have a removable tank or if not how I can get old fuel out without continuing to flush it with expensive new fuel.
Problem 2) trim will not work. Motor sounds like it is working when pushing trim button up or down but it don’t move. It is Full on fluid.
Problem 3) when key is on there is a loud alarm that is going off even after it starts. It is a small red alarm under dash really don’t know what it is going off for. While running it never shuts off. It is full on oil and I have check everything I can think of that it could be for.

 

[Scott Danforth]

tank is most likely built in

drain the tank

pull the sender, fill tank with simple green and hot water. drive down the bumpiest road you can find
drain tank

repeat 3-4 times until the inside of the tank is clean

drain tank, using a rag on a stick, get the remaining water from the corners of the tank.

check to make sure the oil tank is actually pumping oil and the float works.

 

[Tuckerboy1]

I guess the big question is we’re is the top of the tank. Must be I have to remove the floor just behind the motor?

 

[Tuckerboy1]

I guess the big question is we’re is the top of the tank. Must be I have to remove the floor just behind the motor?