[QUOTE=I would not recommend using any anti-vibration mounts on a gas two stroke engine.[/QUOTE]

I have a Great Planes Big Stick, and my engine is the O.S. GGT-15 which is a gas engine only it doesn't use an ignition system - it comes with their special G5 glowplug.
My airplane was vibrating and resonating like mad on the plastic mounts, and no my prop was not unbalanced.
The difference with the Dubro Quiet Mount is amazing. The sound is really softer.
And I have 3 other gas engines, an RCGF .15, an Evolution .10 and an AGM-30, all been modified with adapter in the head to take the same OS G5 glowplug (Evolution didn't need the adapter as used a smaller sparkplug in first place), and so dispensing with the ignition systems that came with the engines originally. ALL of these engines run fine at same rpm as expected with their respective ignition systems, and all sound altogether quieter and smoother on their Dubro Quiet mounts.