My brother also has a 735 and called with a problem in that the feed rollers quit working. He removed the top and end covers to reveal the drive gears and chain. He said the front gear which is run off the motor had sheared the shear pin/key way. He found one locally for a couple of bucks, replaced it and it sheared again. He bought two more and when assembling it, he realized that the rear roller shaft had seized up and as it was driven by the front gear, was the root of the problem. Has anyone experienced this problem?