Why Use Fuel Stabilizer When Storing Your Motorcycle For The Winter

After several months of storage, a reader’s bike wouldn’t run right. What happened to his fuel?

Gas—just like milk—goes bad over time. This can wreak havoc on your fuel lines and fuel delivery system, so protect your stored bike with a fuel stabilizer.
See all of that gunk inside the carb? That’s why you use a fuel stabilizer.Motorcyclist

When storing your motorcycle for the winter, one tip is to put some fuel stabilizer in your tank and run your bike for a minute so the stabilizer gets a chance to run through your fuel system. This helps the fuel so it doesn't start breaking down in your tank and in your fuel lines. Meaning that when you pull your bike out for the first spring ride, you'll ride off without a hiccup.

But, there are problems if you add too much or too little fuel stabilizer to your motorcycle:

Q: Last winter, when I put my bike up for storage, I bought some fuel stabilizer to keep the gas from gunking up the engine and fuel injectors. I poured a bottle of it into the tank, and the bike sat for several months before the weather warmed up enough to go for a ride.

But after I started the engine and rode it awhile, it started making loud pinging sounds, like detonation, and wouldn't run right until I drained the tank and put fresh gas in it. I thought the fuel stabilizer was supposed to prevent this. Why do you and every other magazine recommend using a fuel stabilizer over the winter?

Mike Curry
Seattle, WA

A: You didn't say what kind of fuel stabilizer you used, but it sounds like you used too much. It doesn't take a lot—only a few ounces for a full tank—to treat the entire fuel supply and protect the carburetors or fuel-injection system. Any more than that and you dilute the gasoline so much you're likely to get detonation and a loss of power.

To avoid this happening again, read and follow the label directions. Sta-Bil fuel stabilizer, for example, recommends using just 1 ounce for up to 2.5 gallons of gas and starting with a tank that’s almost full to prevent condensation from forming inside the tank over the winter. After putting the stabilizer in the gas, slosh it around. Then start the engine and run it for five minutes to make sure the stabilizer circulates through the entire fuel system—and to keep your carbs from looking like this one.

Other winter-storage tips include lifting the bike up off the tires so they don't get flat spots from sitting in place for so long or slightly over-inflating them if you can't get them off the ground. If you park your bike on the kickstand, leave the transmission in gear so you don't accidentally knock it over while you're lugging firewood or your snowblower out of the garage.

How To Add Fuel Stabilizer To Your Motorcycle

  • Step 1: Read the instructions on the bottle—yes, we're reminding you
  • Step 2: Add the appropriate amount of fuel stabilizer and fill with gasoline
  • Step 3: Ride around your block and park your bike in its winter sleeping spot
  • Step 4: Finish winterizing your motorcycle
  • Step 5: Wait till it gets warmer and you can ride again