Bad Fuel

[westcoastv20]

New boat (90 V20), had been stored for two years with 40 gallons on board. Our mechanic told us to remove half the fuel. Mix in some carbon guard with high octane replacement gas.

Had a fuel polisher, tell me i should get rid of all of the gas, clean the tank, etc. Then refill with all new gas. Not sure if he was just saying that becuase he wanted to charge me to do it, or if that is good advice.

Just don't want to cause problems on the engine we just had repaired.

Any ideas from the forum?

[spareparts]

removing the old fuel is always the best idea, fuel starts loosing its octane after sitting less than 90 days. you might be able to get away with taking half out, but whats a replacement power head worth? It won't take much to detonate a piston with old gas. Inboards and I/O's can be more tolerant of old gas, but why risk it. I tell all my customers to keep the tank low(the whole condensation thing is BS)and add fresh fuel right before they take the boat out, that way, they always have the freshest fuel

[Destroyer]

Take the old gas out and use it in your lawnmower or snowblower. They don't cost near as much as a new powerhead. Like Spare said, fresh gas is ALWAYS the right thing to do.

[westcoastv20]

Thanks Destroyer and Spareparts. Looks like new fuel, especially since i just had the outboard pretty much re-built.

[spareparts]

if I were you, and knowing its a fresh rebuild, add some 2 cycle oil to the first tank of gas, like you did when it was on its break in, run a double mix the first time out, just in case

[westcoastv20]

Ok,will do. I also was told to use premium (high octane) on the first tank with some Carbon Guard.