The key thing is to check the oil in both the final drive and the transmission compartments. Those tractors were wied in some would transfer the oil from front to rear which is not good and some from rear to front . On the starting. That was a problem and in the spring of 1961 Oliver came out and put an expermental head on the tractor we had sold that would not start. End of problem. The change was they put valve seats in the head and probably set the recession for the valves correctly. It started good then.