Originally Posted by 2door
Any resilient material between the engine and the bike frame does not eliminate vibrations which are common to a 2 cycle, single cylinder engine. The soft mounts will only transfer the vibrations to the fasteners [& exacerbate mount/motor movement]. This is where so many people get into trouble with broken studs and such. Mount the engine as solid to the frame as you can get it with good contact area throughout the mounting surfaces. Yes, the inherent vibrations will then be transferred to the frame where you'll feel it but you'll benefit from longer fastener life and other parts that will be effected by a soft mounted engine. This isn't theory but has been proven time and again by many builders.
^ sorry, it's far easier to C&P Tom's well phrased post than to type it again lol