Are you receiving a low oil or no oil warning? Low oil would be 4 short beeps every 2 minutes from the alarm. No oil would be a continuous tone from the alarm and wide open throttle would be limited to 3,000 RPMs. If you can, provide the engine serial number. The picture below will show you where to find the serial number on the engine.
My Son, Kurt, says the engine gives 2 short beeps does nothing for 5 minutes or so and then does it again. He will call me back with the serial number and I will provide it to you. You can call me toll free at XXX-XXX-XXXX X 1340 or on my Miami cell phone at XXX-XXX-XXXX..
The serial number for the engine is OT554751
It could easily be the sensor or float in the oil tank bad. If this were the case you would be getting 4 beeps every 2 minutes, so have him check on that. The oil tank mounted on the engine should always be full. If it's low at all there's a problem in the delivery system between the main tank and it or the main tank is very low to empty.
The easiest way to test this situation is to bypass the oil tank sensor for now. There will be two blue wires coming out of the top of the oil tank that plug back into the engine wiring harness, disconnect both wires. On the two wires that go back to the engine wiring harness, use a piece of wire or paper clip to tie them together. If this eliminates the alarm then you know the problem is in the sensor or the float. Just let me know what you find and we can go on to figuring out the exact problem.