Just got back from a great ride in the peaks but half way through the day my bike suddenly lost all of it's top end power and was cutting out. Was also misfireing. Bike has only done 10 hours. Haven't had chance to strip it down yet. But was going to drain the fuel and clean the fuel pump. Any1 else had this problem or any idea what it is as I'm no mechanic. And my knowledge of 4 strokes is poor.