Soft mounting or vibration absorbing mounts will ruin an engine. Always secure the engine rigidly to an airframe. This will increase the overall mass and thus the vibration. Soft mounting will focus all the energy of the moving piston into the engine. It’s a sure way to wreck one. Gasoline engines do not need to be broken in on a test stand like the nitro ones. Long periods of static running on a test stand is another sure way of destroying an engine. Rigidly mount the engine in your plane with the needle valves set at the manufacturers recommended settings and fly. I believe the VVRC engines come with a Walbro carburetor. If they do not recommend any needle valve settings you can use 1 ½ turns out for the low speed needle valve and 1 out for the high speed. Dan.