ORIGINAL: DMcQuinn
Vibration here can cause wood screws to come loose. Use the nuts with the plastic inserts that keep them from loosening.
nylon filed engine mounts, like the ones included in most ARFs and kits, hold both machine and self tapping screws (wood screws) exceptionally well and are very resistant to loosening from vibration because the nylon taps a very tight fit because of compression, it's the same as having the lock nut previously mentioned, you know the ones with the nylon in the end of them
kc