If you’re traveling up, up, up a mountain with your quad (to a higher altitude than where you live) you’ll need to adjust the carburetor to keep the air/fuel mixture correct. The general rule for jetting is to drop one main jet size for every 2,000 feet of elevation increase. You can also go one clip position leaner on the needle jet.
This is a good start for high-altitude adventuring, but depending on the temperature and humidity, you may need to go leaner or a touch richer. If carb adjustments aren’t your thing, bring it to a mechanic and explain what altitude you’ll be riding at so he can make the correct adjustments.