I was at a race yesterday and the first three motto's my bike would just quit or die at certain points on the track. It acted like it wasnt getting any gas. At one point on the track around a uphill right hand turn it would die going around this turn everytime. I first check the gas line pulled it off the carb and turned the fuel on. It was fine (gas came through). Second I drained the carb from the bolt at the bottom of the carb. I didnt see any dirt or contaminates in the drain bolt. I turned the fuel on with the drain bolt out and gas came out. I then noticed the sparkplug cap was up a little so I pushed it down but it would pop back up some. I pulled the cap up to take it out and only the top portion came off....the bottom long part stayed on the plug. I then changed to a different gas which was plain 93 octane cause I had the 110 cam 2 in it mixed with 93 octane (half and half). On the last motto it ran fine no issues but one time it died going around a turn. I was wondering if marathon 93 octane contained ethnol which causes these 4-strokes to die. Or would it have been my sparkplug cap being up a little that was causeing the dieing?