I have a sportster LT, sometimes when I throttle up, the right engine hesitates and revs slowly to about 4000, as if the engine is under more of a load than the left engine witch jumps to about 6800 instantly. One member said to check the intake manifold for cracks. I did a penatrant test on the intake and there were no cracks. Dint know what to do or look for next. Does anyone have any suggestions?