I have a 1971 1200A OMC skid steer that the engine keeps shutting down under a load. I can let it rest for about 30 to 60 seconds and it will fire back up and run for 3 to 5 min. before it bogs down again. Sometimes when I feel it begin lose RPM, I can slow down the Variable Speed and the and the accelerator and let it idle at low RPM. After 30 to 60 seconds I can idle back up and work for 3 to 5 min before the event repeats itself. Any Thoughts ??