If you absolutely have to store your ATV outside, it’s important to know a few things in order to protect your ATV both in the winter and throughout the rest of the year.
Be sure to let your engine turn over once or twice every month (without starting it) during the winter to ensure that all the components stay well lubricated.
You will want to get a battery tender to keep your battery in good shape over the winter months. Prolonged periods of nonuse will cause your battery to die pretty quickly.
In order to protect your ATV tires during storage outside, you need to inflate them to their maximum capacity. Tires tend to slowly deflate over time and this is best way to to keep them inflated without weekly inflating them all winter.
Finally, you need to invest in a good ATV cover to protect your ATV when stored outside. It is recommended you not use a plastic tarp, but rather purchase a breathable fabric.