1.Take both blades off the Heli
2.Put the blades up against eachother to see if they line up(if not bend them to be symetrical to eachother.
3.Balance them by bolting them together with a long round head bolt and set the blades(ends of the bolts) one each side or the object(vice works well) to alow them to pivot.
4. Put tape(Electrical on bottom works good)on the blades until they don't move
5.Put back on heli and enjoy smoother flight.

tomflier