When i get into my powerband(8K-11K rpm) it's not smooth, it feels erratic. If i give it a bit less or open up the throttle it seems to smooth out. I changed the spark plugs and cleaned my air filter but it didn't fix the problem. My plugs were black which means i'm running a bit rich. Will running rich cause it to run rough at high rpms?
could my carbs possibly be dirty?