My 06 660 grizz had been sitting for 4 years and cleaned the carb jets and a new battery and it took right off. When driving along at get to about 27-30 mph it cuts out and the reverse on the head unit starts.flashing. it dosnt die but just cuts out and i can recycle the throttle and keep driving untel 27mph and it does it again. At the dealership they said the head unit was going bad so i am wondering if thats part of it or if its something else??

Thanks