Today during normal operation ( cutting at full throttle, blades engaged ) the engine ( 13hp Kawasaki ) started to cut out in the same fashion as if you let go of the handles and the kill switch shut the engine down. I hit the switch to disengage the blades and it fired up and continued to run like nothing happened. I then re-engaged the blades and had the same cutting out effect. I shut it off then started it again and was able to resume normal operation , this happened about three times. Anyone have an idea whats going on?