I am going to be mowing a large sized property that has a very large embankment on one side that is about a 45 degree angle. I was quite surprised to hear that the previous company mowed it with a rider. I have two mowers in my fleet. An Exmark Phaser and a Sears Craftsman. Do I need to be concerned with oil not circulating through the engine on either two of these machines because of the angle these riding mowers would be on?