You're right, I did see movement in the coil mount as I rotated the magnets past, so I secured it with a steel zip tie around the coil mount and around the back side of the muffler. Now, there is no movement when I rotate the flywheel. I'll run it a bit on the ground to make sure everything is holding up OK before I fly it. Also, I don't think it would be that hard to replace the hacked up saw portion with an aluminum bracket to hold the coil. I think it could be made with small pieces of aluminum L channel to mount the coil in the exact position. I may still pursue this if I don't go the gas/glow route.