#2 Motors. I will use only certified, commercially-made model rocket motors, and will not tamper with these motors or use them for any purposes except those recommended by the manufacturer. Estes own chart says: "Do not fly a rocket/engine combination whose lift-off weight exceeds the recommended maximum lift-off weight". C6 "Max Lift Wt." is 113g , but the rocket weighs at least 141g (ours weighed more). Note this has already been mentioned in this thread. Note specifically that the avg. T/W ratio 4.7/1.4 or 3.4/1 https://estesrockets.com/wp-content/uploads/Educator/Estes_Engine_Chart.pdf Very nice!