Sent mine in for updates. It got a new pistion and needed bearings? (I don't know why the bearings went out, started sounding funny, I sent it in, they fix it and send it back) I believe the new piston gives a slighlty lower compression ratio.
Maybe it helps in the shaky department. I bolted it on per DA recommendation, which is against solid wood, not stand offs. Mine may shake a little more noticably than my 50cc, but I think that is expected, no?

Plus, it only shakes on the ground at idle, once you give it some juice, all is good and smooth. It's a thumper, a beast, that's why I got it.