Toki 42 Problems and Questions

Does anyone have any experience with the Toki 42, I got it with my sceadu 30 combo from MRC. I went through a gallon of 30% and then on the second flight of my 2nd gallon the damn thing seized and snapped the connecting rod and cracked the piston. I sent it in and they repaired it as a warranty, but I want to know why it did that. Again it is in a Sceadu 30 kit and I am running coolpower 30% at 4 1/4 turns (4 - 4 1/2 is recommended). I just don't want to be dealing with this on a constant basis.