Got this unit in exchange for a set of tire chains that I had traded some labor for. So a tractor for about 3 hours of labor. The price was right I figure. The guy figured the motor was blown. I have since tried and it starts right up. Heres the thing when it warms up its like suddenly the exhaust valve sticks open and it looses compression. Im guessing thats what happens based on how it sounds and the flames shooting out of the very short muffler on it. Guess Ill have to tear the engine down and check what shape its all in. Apparently it has been run out of oil. Maybe the valve guide is scored? Who knows. Hopefully the engine can be repaired. The serial # is 9631859. The guy said its a 1972. The manual for it from Ingersoll mentions it being a 1969 or 1970. Is some one able to tell me what year it likely is?