I got some directeducation a few years ago in regard to rubber iso mounts....

In a hurry to get my new 38cc gas 2 stroke engine bench run,I didn'tuse an iso mount. The test stand was simply screwed onto my backyard deck railing and engine was started. One should understand how much "dead"woodis in a back yard deck....a couple tons or more which should absorb lots and lots of vibes.Well.......

I happened to be in bare feet during the first couple runs. The buzz to my feet was uncomfortable so I completed the iso mount I was building and did some more test runs. Again in bare feet but this time, the buzz was gone. This really drove the point of soft iso mounts home.

Point is it doesn't matter how much wood the fuse is made from. Vibes from the size engines we run today, will kill the equipment over short time.

One should not confuse the high frequencybut invisible, destructive vibration at full revs of the hard mounted engine with the low frequency, non-destructivebut very visible shake at idle that rubber iso mounts often display. The rubber iso mounts really isolate the airframe well from the engine at revs higher than idle