Originally Posted by barry123400

Just for the hell of it and the time required. Set the balancer to the approved degrees setting for your 603 model. Take a small mirror and check for the indicator tang in the injection pump being present and more or less centered.

Your fuel milage to me sounds low perhaps for a 603. It would not take too much decreased efficiency to cause the problem. Next time out also come to a stop without using the brakes after a few miles and verify the wheels are all the same temperature. Some dragging brakes could be present.