Mine had a simjet 1200 and flew at 1/4 to 1/2 throttle with authority. Takeoff was about 350 ft on a 500 ft ashphalt strip. backed out to 1/2 throttle before first turnout. Remember, no matter WHAT guys will tell you, the Kangaroo was DESIGNED for a 11lb sophia tubine. They flew the crap out of them at metro. at 150+ with these. These were also the original roos that were heavier than the new ones. Russ