well my uncle bought a brand new 450 and it wants to die ever time he lets off the gas what do you think could be wrong with it

 

Mine did the same thing for a while. I just got on it, put some time on it and it went away. Might be that the motors tight when new and loosens up enough during break-in. I haven't had a problem after if was broke in.

Rude Dog

 

a new hot tight motor will cause this