I saw on some posts and several instructional videos that you could use an old inner tube between the mounting hardware and the frame to dampen engine vibration. I was attempting to do this and it's difficult to get the inner tube in and keep it in place as you tighten everything up. And as soon as you loosen things to adjust it falls out. I had some liquid electrical tape and applied it to the mounting hardware and engine bracket and it worked really well. 2 coats gives you a nice layer of rubber that lets adjust things without scratching the frame or fumbling with old inner tube. Check it out.