07 rev stutters

[markoo]

I have a 07 rev 800 that idles good and revs good. Problem is between 4500 and 6000 rpm it stutters and doesn't run clean. I replaced plugs and boots. drained carbs(clean) checked for loose hoses and wires. The exhaust valves pull down when it's running and both open right around 6000rpm and then it runs clean. Any ideas what could be wrong?

 

[brahm]

double check your rave valve hoses, make sure even if they are on there are no holes, or the ends are frayed use zip ties, or clamps to lock em down. The worst one is on the mag side of carbs. I had to clamp it, and run a double zip tie to pull it towards the fitting to keep it in place.