my 700 has recently started back firing every now and then when going down a hill out of the gas, if it acts like its about to and you blurp the gas it will keep from doing it. The rhino has 1300 miles on it and only mods are sheave and spring, nothing to the motor but a raptor spark plug. The intake plastic cover that goes over the top of the airbox inlet fell off but i wouldnt think that little bit of diff should matter, but maybe it does. I run 93octane fuel as well. Any ideas why it would be backfiring?