Since it seems to be shaking the entire bird the mains are a good place to start, I think that the bearings for your tail drive gear would also be suspect. Also have a good look at your motor mount and the condition of your main drive gear. </p>

As for which Scorpion motor, I would think that the model HK-3026 V2  1000KV should be sufficent and the ESC should be the 60 amp as the 100 is overkill. You can find your upgrades and the Scorpion produts at the link below.</p>

http://www.helidirect.com/</p>

</p>

Watch Your Six, Tr1n1ty.</p>