I have a Kubota G1800 lawn tractor three cyl diesel. When the mower tilts to either side, after a few seconds it starts to run rough and the engine starts loping trying to die, and sometimes it does die, but will start right back up. If I stop the mower and shut of the blades off, the engine will pick back up and will return to a smooth idle. It only happens when the mower tilts to one side of the other on a slop. Could it be some type of fuel delivery problem or a fuel filter?