Have a 2014 pro only mods are GGB can,bikeman durability kit,oil pump turned up,kurts clutching and gear down kit. 99% of the time the sled runs flawless, I love it. Every now and then it bogs and falls on its face, it'll do it once then go back to running normal. I added some fuel additive( seafoam) in case water got in the fuel and I also swapped the plugs out and it still does it. Any ideas? I was thinking maybe a bad weight bushing?