In this Pilot Short Story produced by the AOPA Air Safety Institute, a pilot must make a split-second decision: either abort his takeoff or continue the flight up into uncertainty. Noting that his airplane doesn't usually shake excessively during the takeoff roll, the pilot cuts the power and safely taxis off the runway. After discovering that the number four exhaust valve was stuck, he concludes the lesson learned from this experience is to trust that pestering feeling when something doesn't feel right.