Originally Posted by ReiMon
Absolutly isolate.. The fact is if you ridgid mount it the action of the motor will result in a 5k plus harmonic. Never mind that you feel it in your ass, your motor feels it. I've broken 2 carbs and blown 3head gaskets from the vibration. **** rubber, Spring type shocks work better. My bike is in it's third season now. I've broken 3 sets of studs off the rear mounts. The keys is a spring loaded dynamic type chain tensioner to take up the slack of the slight engin movement and spring mount the engine... Only allow enough movement to disapate the ocililation created by the piston action but DONT ridgid mount or you'll be tightening your head bolts every 5 miles and going back to find your aircleaner every2.
Sorry but I and many experienced builders will have to disagree with your thinking.
This isn't based on theory but experience. An engine that is mounted solidly to the bike frame will not compromise the mounts or mount fasteners. If you've broken three sets of mounting studs that should be telling you something. Springs, rubber, whatever, any resilient action between the engine and frame will eventually come back to bite you.