When Is Gasoline Like Milk?

When is Gasoline Like Milk?

Tell me if you’ve heard this one before: A man fires up his outboard for the first outing of the season. He didn’t put any fuel stabilizer in the tank before letting the boat sit for many months. But
guess what? The outboard fires right up. No problem. He tops off the
tank with gasoline and takes the boat out on the water for a fun
afternoon. He soon discovers getting on plane and maintaining speed
takes a lot more throttle than it did last season. He doesn’t recognize,
though, until the engine has stopped running, that the outboard has
been detonating – a dangerous and destructive result of running on fuel
that has deteriorated to the point of losing its original octane rating.
Ultimately, he’s forced to find a tow back to the dock, and he soon
learns his engine has been seriously compromised.

"This scenario plays itself out every spring," said John Wilkinson, Yamaha Marine Group customer relations representative. "Customers try to run their outboards on bad gasoline, and it ends in damage or complete
engine failure."The best way to protect your boat from bad
gasoline is to imagine that the gasoline is milk, and then ask yourself
these questions:

1. Does milk last forever? No.

2. Is spoiled milk good for your body? No.

3. Does adding fresh milk to spoiled milk improve the spoiled milk? No.

4. Does adding chocolate to the spoiled milk make it okay to drink? No.

Does gasoline last forever?

No. Gasoline, kept in a sealed container, has a shelf life of approximately 30 to 90 days—depending upon conditions*—before deterioration begins. If you add the correct amount
of fuel stabilizer, that shelf life increases to approximately one
year—depending upon conditions*. The process of oxidation that takes
place in the gasoline causes the fuel to lose its octane rating. The
octane rating is what gives the gasoline the measure of its ability to
burn progressively and regularly in the combustion chamber.

Is spoiled gasoline good for your outboard?

Absolutely not. In fuel with low octane, the fuel/air mixture doesn’t burn regularly and reignites in the combustion chamber after the spark plug has already tried to ignite it. It’s called
detonation, and it’s akin to throwing rocks at the piston. It creates
damage to the piston and other internal parts.

Does adding fresh gasoline to spoiled gasoline improve the gasoline?

No. The best thing to do with untreated (unstabilized) gasoline that has been stored for more than 90 days might be to drain it from the tank and fuel system, then refill the tank with fresh fuel
before trying to start the motor.

Does adding fuel stabilizer to spoiled gasoline improve the gasoline?

No. Fuel stabilizer can extend the storage life of gasoline, but only if the gasoline is fresh to begin with.

"There are two things boaters can do to avoid engine damage due to detonation," said Wilkinson. "Always us a fuel stabilizer, particularly when storing fuel in the off season. " If you find you have forgotten
to do so, then drain the tank and fill it with fresh fuel."

* Conditions include temperature, humidity and type of storage container.

Source: Yamaha