I have had good luck with copperheads, just make sure it is all the way up inside of the motor. If you are not using the aerotech controller then you can tape one side of your alligator clips and alternate their position on the copperhead, or you can heat up the tail with a lighter, this will seperate the two pieces and you can clip them individually then. When you go top push the button, make sure you hold it down till it launches and have a well charged 12v battery.