I have seen the problem mentioned of vibrations occurring during startup and shut down I to suffered from this buts here’s what I did.
1.)Went to HD and got a 4ft pcs of 1-3/8”x1-3/8” heavy gage slotted angle. Cut into (2) pcs 22” +/ to run front to back. Pcs are fit in under the stand top either under the existing stiffeners or over top aligned to use existing bolts from saw body and motor mount. Tighten every thing up good and snug. Be careful with the casting bolts, over tighten and you will break the casting.
2.)I bought a rubber mat with holes in about 1/4” to 3/8” thick. Cut it big enough for motor mount plate and used it instead of the grommets. Tighten motor down after aligning the motor and saw pulleys
3.)The biggest thing I find is not and I repeat not to over tighten the belt by moving the motor to far back. I have found that having the belt as loose as possible with out slipping is the best.
It has reduced almost all of the vibrations I had to a level not even noticeable by me, and I’m really anal about things. Give it a try it cost me $13 bucks
If It\'s Not Broke, Fix It Anyway!