Building my first gas powered plane.Senior telemaster using a 22cc engine, never thought of soft mounts, are they neccessary on gassers?

If it is a garden appliance engine, it will like hard mounting better. (the plane not!)
OTOH, All hand-held garden appliances have the motor soft-mounted, so longevity should not suffer either way.

I like to use a soft mount with a limited free movement of about 0.1mm (0.004") either way. Grommets used are 40 shore (very soft)

high frequency dampers -good idea
there is a lot of banter about mounts which allow the engine to flail around --as we once did with our 1.4 four cycle glo engines
The only setup I ever found which worked -- was to mount the engine such that it was free to rotate ONLY on it's crankshaft centerline-- damped in movement by some means - I used an adjustable natural rubber snubber - this eliminated the tremendous thump at low rpms BUT any external exhaust setup either restricted the movement -or got broken.
On our large engines --letting them shake about is a distaster.

Soft mounts are amateurist. Not only are they damaging to the engine but are simply a waste of money....[8D]

I am just thinking a "soft mount" for my MVVS 26 with radial mount. Is a piece of 6mm think industrial rubber between the plate and firewall enough or should I think something else? Anyone can share pictures of succesful soft mount installs?

Still -23 degrees celsius(-9F) here so I have plenty of time before summer

For what it may be worth to you:
I am using the Evolution 26 GT -almost same engine , on a Funtana 90
there are no modifications to the mounting or the airframe . Nothing shakes or rattles around . the servos are all tight after a few months of flying.
Honestly I see no advantage to changing from the simple hard plastic mount which came with the kit and I used to fit the engine .

The large slab will not work, because the resonant frequency is too high. This is the system I use (4 each)
On small glow, I use only three.

I have used soft mounts with the mvvs 26cc gas and am now busy removing them all why?

its just not necessary and all they do is add weight.

currently using a funtana 90 and cermark sukhoi, no soft mounts no problems

Your plane will live longer with some form of vibration isolator. The isolater blocks the high frequency, high G-force alternating forces that stem from any internal combustion engine, and add a total of about one ounce. With a bit of good design jugling, that extra weight can be saved from the firewall region, because the peak forces acting on this area will be smaller.
The effect on the airframe can be judged by plane resonance, and the noise it generates by virtue of the large sound radiating planes like wings. A reduction of 3 dB has been noted in some cases.
These little gadgets in my previous posting realy do some serious work for the total plane concept, and do not just add weight.

Here's my MVVS on a Dubro Vibration mount. I'm very happy with it, it's worth the extra 2 ozs. to me.

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