Hi guys I have a 2017 Grizzly 708 SE with an HMF Titan exhaust, EHS Racing Air Filter and lid. My bike Backfires like it shooting Ducks from full throttle to off throttle. I have tried HMF tune and it still Backfires and the Pipe is BLUE all the way to the Can. I am a little worried about changing the tune too much with out a Dyno and C/O reader? Thanks for the help guys.