ok so my buddies bike was working fine and out of no where the revolutions wont go past 5k like a rev limiter and just bounces there so we took apart the bike clean the air flow checked the pump and tracked down a few lines and everything seems to be in place and correct except it wont freaking go past 5 k anybody have any ideas as to what it could be

 

I had a similar experience in the past like this. The alternator belt had broke and therefore limited the rpms because of the lack of voltage supplied to the coils. I was like wtf? My 7 has a belt? Sure enough