When running it will miss a little and then when running at a high speed then letting of the gas will back fire. Also right after machine is shut off it will backfire. Any suggestions would be great thanks.
IAN

 

Lots and lots of post like this lately! The backfire indicates a lean condition. If it was running fine before, you probably have a clogged slow (idle/pilot) jet. This happens when the quad sits around and fuel dries up and gums up the jet.

Do a carb cleaning, and pay particular attention to the slow jet! After you reinstall the carb, also adjust your fuel screw (it is the fine adjustment for the slow jet).