I assume your tank is hard mounted maybe under the bow and is darn near impossible to remove? Mine is the same set-up. I've tried the cheap siphons that didn't work. Best solution I found was using my Holley electrical fuel pump from my old truck to suck out the old fuel.
Those 10 dollar pumps that you hook to a drill should do fine.
Or any hose as long as you can get the other end below the tank, you can put the cap (block the vent) on and blow in the hose (alot, one big breath) then stick the end in a can you want the gas in, the pressure you blow in will force the gas to start to siphon out.
This assumes you have no anti-siphon valve.
Dont bother with those bulb type pumps from the autoshops and like. They dont work.
The one from HF has several hose sizes. Attach to whatever your motor gets it's gas from and pump. I pumped out 10 gallons by hand pretty quickly. Doesnt take long. I didnt bother attaching the hose on the "output" end. Just had it facing into my small gas tank and pump until it was full.
