I have a PNP pulse xt and the spinner and prop nut everything keep flying off it hasnt done it in air but it has done it 3 times on the ground starting it. Anyone know what can cause this? I use a starter is it spining it off? I have had many other glow planes and all of them evolution engines and start the same way but for some reason this combo always fly off.

Any help would be great didnt know exactly where to post this.
-JR