My 2008 500 HO seems to start breaking up under acceleration. Particularly on steep inclines and rough terrain. Replaced the spark plug, fuel filter and fuel pump with no change. Seems much more prevalent onced warmed up. If engine is not under load it will rev right up. Under load skips like crazy. I took the carb apart and found nothing wrong. The inside of the carb looked pristine. I still think something with the carb. If anyone can point me in the right direction it would be greatly appreciated.

 

Just a thought , remove the flywheel cover & remove the nut to see if the key is broken, if half the key is in one place & the other half is in another it's broken, should only see 1 key & it should be nice & square if it's not broke. Could very well be the problem .

 

Vacume leak?