Yeh Matt, Prop too big!! Good speed but runs out of puff after about 30 meters even with a push start. Didn`t bother with a vid. Next step, 17 double through a Carson gearbox (about 2:1) and retry the 50m.m. prop. Also tried a 41m.m. prop in original set up with 21 double and 17 double, still will not hold it`s speed. It did come close with the 17 double but washed off too much pace when cornering and then would not get up on the plane without a push start.[&o] Never mind, gearbox arriving next week and she`s stripped out AGAIN ready for another try. I will keep you posted. I still have 3.5c.c. Collari Buggy Motor and Pipe which weighs no more than 540 and 3000mah battery. Maybe that is the way to go!!!!