I have an Indy 500 it bogs some times and somtimes not. When it does the rpms will only go to 5000 rpm and hold there you can play with the throttle and it dont make a difference. Then out of no where it will run perfect rev up and cruse at 65 mph why does it bog somtimes. I have cleaned the carbs and ran polaris carbon cleaner threw the system. I moved the clip up on the needel one notch also it is at the second from the top. Whats next to look at?