2001 Yamaha Grizzly 600 not running. Backfires and turns off. Help?!

So I just bought a 2001 grizzly 600 for $800. I bought it knowing it wouldn t start. I have not adjusted anything and when I try to start it, it turns over and it shows signs of life and it turns on when I pump the gas but it only turn on if I give it gas. Even then it doesn t rev up, it just bogs up and down then eventually turns off. Right before it turns off it back fires and the carb pops off the sleeve. Is this an adjustment I have to do with the carb? I don t have an air filter on it right now. Could that be a problem? Please help.

Ignore: Yamaha, Honda, Carburetor, Grizzly, 600, 660,

Read more: 2001 Yamaha Grizzly 600 not running. Backfires and turns off. Help?!