fuel tank level

[ghoss]

I just bought a1997 nitro 700tf with a 90hp johnson,my question is how small of an amount of gas can i run in the tank because i will mostly be idleling along.The lakes we fish have hp limit and i donot want to have too much gas in tank . I believe the tank is 24gallons. It has half a tank in it now and i must drain it because its 3 years old.Any advice would be appreciated.

 

[GA_Boater]

Are you switching to a smaller motor? I would just use a 3 or 6 gallon portable tank.

 

[ghoss]

no not right away we will hit a larger lake every once in awhile and the motor is too damn heavy to keep swaping out. ky is proposing allowing idle speed only on larger than 10hp but that wont be until july. Thanks for the response

 

[pckeen]

First - good call on draining the existing tanks.

If your concern is gas going bad because you won't burn through a tank for a long time, then add some fuel stabilizer - Sta Bil of Sea Foam - that will make it last for at least a year. There's no 'minimum' amount of gas you need to put in it - fill it a third full and you should run fine - if you aren't heading far from dock, keep a jerry can full. Only thing to be aware of is a partly full tank allows condensation to build up - a full tank provides better protection.

 

[UncleWillie]

Just because the gas is 3 years old is not a reason to suspect that there is anything wrong with it.
If you have 12 gallons it shouldn't last more than 20-30 hours if idling the full time.
Even less if you get on plane a few times.
I would keep running the gas that you have, and keep 3 to 6 gallons of spare fuel on board.
Once you run out of fuel, you will know where the bottom of the usable fuel level is.
Add the spare gas to the tank to finish the trip.

Keep in mind that continuous running of the engine at idle speed all day will not do it any good.
You will want to open it up for at least 10-15 minutes every few hours.

 

[achris]

Any fuel more than 6 months old is suspect. Anything 3 years old WILL damage the engine.

And if you're just going to be idling around, and not far from shore, why not completely drain and dry out the existing built-in tank and use a couple of 'remote' 5 gallon tanks. Easy to move around, and when the day is done, toss the remaining fuel in the car.... Just fill the 5 gallon tank(s) on the day you plan to use the boat. That way the fuel is always fresh, and the unused stuff, goes in the car and isn't wasted...

Chris......