See the white pad between the mount plate and frame under the Ubolt?
Notice the flattened frame tube? Caused by overtightening to try and stop inevitable engine movement caused by rubber.
Notice the visible distortion and damage on the chunk of downtube still visible?
Also notice the damaged area (paint worn off where engine rubbed) clearly visible on the broken section of seatpost tube from VIBRATION causing ENGINE MOVEMENT.
DON'T USE RUBBER OR ANY TYPE OF COMPRESSIBLE MATERIAL IN YOUR MOTOR MOUNTS.
*Wipes spittle off monitor screen*
If more is better, then too much is just enough.
If you can't afford it, build it yourself.