Was breaking in the brand new XB today with idling for a tank, coolkng down, 1/4 throttle for a tank etc... Each tank it ran better and peppier... Got to 3/4 throttle tank and was running great until all of the sudden at 1/2 throttle and above it would not go any faster but just continuously POP POP POP until i pulled it close to me and it died.. Now it wont restart... Seems like its getting fuel, plug was a nice tannish color... Wtf happened to make it start popping all the sudden at half and above throttle when it HAD been running so well... Would you change plug? Anything i can look for? Its got less than 2 hrs running time... THANKS FOR ANY HELP