Getting Stablized Fuel To Engine

[jaymoussy]

In winterizing my Montauk 170's Mercury 90-HP FOURSTROKE EFI engine for the first time, I got some fresh gasoline with Sta-Bil and ran the motor at idle speed on muffs for approximately 10 minutes on the stock fuel tank and line. Was that enough time for the new gasoline to reach the motor, internal filters, and injectors?

[Jefecinco]

Depends on the length of the fuel line. I believe so. One way to ensure the fresh fuel reaches the cylinders would be to run the fuel tank dry of old fuel before filling with fresh fuel and stabilizer. I put stabilizer in every tank full year round.

[jimh]

These modern engines at idle speed do not consume very much fuel. Even large-displacement high-horsepower engines at idle only burn a fraction of a gallon per hour. For example, my 225-HP modern engine only consumes about 0.2-GPH at idle. In ten minutes we have only 0.17-hour, so my engine would only consume 0.17 x 0.2 = 0.03-gallons or just over 4-ounces of fuel.

I don't think 4-ounces of fuel will be able to completely fill the volume of the fuel system. There is at least that much volume in the fuel tank pick-up, the fuel hose, the primer bulb, and the canister filter.

I try to always run the boat on stabilized fuel during the last on-the-water operation of the season. That way I know several gallons of stabilized fuel has gotten pulled into the fuel system. The entire fuel system should then be filled with stabilized fuel.

In summary: no, ten minutes at idle will not get the new fuel with stabilizer into the entire fuel system.

[macfam]

I'm in complete agreement with Jimh.
Today's engines run 4-10 miles per gallon depending upon size. That is at a normal running rate, not idling.
To do this right, you need to run the boat for enough time to replace at least a full gallon of fuel.
Now.....is this the end of the world? No.
Each year, I store my Toyota pick-up in our seasonal home's garage for several months. And, the gas is NOT STABLIZED.
Never had a problem in 10 years.
Next season, get some fresh gas to start off right. Stabilize every drop all season.......done!

[Phil T]

Fill the bowl of the fuel filter on the motor with stabilized fuel and run.

Use this year's fuel in your mower/leaf or snow blower. Next year, run stabilized fuel all year round.