ZD 331 - while mowing, if I stop for some reason, shut it off and then restart, engage blades, it will go for a short distance before shaking and running very rough then dying. Trying to restart, it will do the same shaking and rough engine before dying. If I leave it for about 45 minutes, it will start with no problems and I can finish mowing. It has been recently serviced by Kubota dealer. They have no idea why it quits on me. Anyone?