I recently bought a 1963? Case 440 4 cylinder gas tractor. It starts great, runs well, but occasional, especially if you are turning and the power steering is engaged or if you are starting out in a 3rd High range or 4th low range and the engine is put under load, it will falter and the engine speed will drop and it will not recover even if you advance the throttle. On most occasions the RPM's will hover around 1000 and the engine will labor and sound like it is under a very heavy load. Sometimes moving the steering wheel so that the power steering is not engaged will cause the engine to recover, but sometimes it will just stall out. It will start again but the the engine speed will still be low but it will eventually recover and may run great another fifteen minutes or more before doing the same thing all over again. I have checked that the carburetor load screw adjustment and it is set to spec and rechecked the plugs, points etc. Any insights or advise you may be able to offer would be gratefully received.

I ran into a simmilar problem with an another tractor. I changed everything plugs,wires,ect. Come to find out somebody changed the sediment bowl but not the hollow bolt, the hose and the hole didn't line up. It was wierd the tractor ran about 3-4 months consent then all of a sudden it starting acting up. Hope this might help.