Tie wraps will work fine if they are large enough. But if you have any amount of flat surface to work with, 2 sided foam tape works very well to keep things in place (keep from sliding)while the tie wraps will hold the motor snug. Just make sure you are not covering up the vents ang check temp often as the tape will melt away. I have an 80 mph wing and the tie wraps are all that hold the motor in.

Joe