Well, I'm somewhat confused about the set up you are using, but is it something along the lines of this?
http://i42.photobucket.com/albums/e3...0112081353.jpg,
at least the front part of that. I think we need a better understanding of what you are doing, but if you see the sprocket attached to the "arm", we ran that six inch sprocket to around a 2 inch one on the keyang motor, and were able to pick up the ball. We just used the plastic caps they give you with those motors, and hard mounted to a keyed half inch axle all the way across...
a good way to mount a lever is maybe attach it straight to the output sprocket, and have an axle to take some load but definitely not all of it, and if you can mounting straight onto the sprocket that helps, and is how we have done arms/levers in the past...
now that I think of it, I don't know how much help I was =x