I'm 17 years old facing felony charges on larceny. I'm getting blamed for stealing a snowmobile?

Did you steal it? You using "blamed" suggests you didn't; we'll go with that. If there's lots of proof against you, don't fight it, just accept it because you can't change it, but that's if there lots. If there's not much proof then just deny it and ask for proof. Tell them the truth because that's easy to do. Explain why you wouldn't steal and get a alibi or a few to defend you.