Do you have a better recommendation for the rubber than the inner tube pieces?
Defective engine!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1
Please don't tell me that.
If the engine is vibrating badly through the entire RPM range...you have a bad engine.
No amount of rubber, or rigid mounting, is going to make it go away.
A lot of these engines will have a bad vibration at a specific RPM. This vibration will dissipate as the engine RPM's increase or decrease.
Some vibrate mid-way when accelerating up to cruising speed.
In other words, you leave from a stop and a bad vibration occurs at 10-15MPH and subsides once you reach 20-25MPH...this is normal for an engine that is out of balance. This is just an example...gearing, tire size, and the RPM that the vibration occurs, will dictate the actual MPH where it happens.
Some of these engines are very smooth until you hit a high RPM. Again this is normal for an engine that is out of balance.
Considering the cost, I have no problem living with an engine that runs smoothly at cruising speed.
If it vibrates like the dickens all the time...the engine is defective and will need to be replaced.
Jim