small engine HELP!!!

Can anyone out there tell me why my snowblower engine won't run unless the choke is full on, and then it runs a MAX RPM. I mean scary MAX RPM. It just stalls when you try to idel it down, or pull the choke off. I don't want to blow the thing up, and it is relatively new, so I'm hesitant to just start tearing it apart.
Anyone have any ideas? Man I hate every engine less than 273 cubic inches.