We have a 130kw Generac generator, model #: 1387720100 that will run fine for a period, then shut down on "High" oil pressure. What could be the problem.

You must first determine what the actual oil pressure is by using a mechanical oil gauge. Then compare this to the reading on the generators control panel. If the control panel is showing much higher then what your mechanical gauge shows then you probably have a bad sensor. If the reading is the same on both the mechanical gauge and the generators control panel and it is somewhere in the vacinity of 55-70 psi this is normal. The alarm might be because of the oil pressure alarm configurations need to be adjusted in the control panel. This needs to be done by a factory certified rep who has the software to link to your generators control panel.

See if it has a low oil pressure switch on the side of the engine if so cut the wire and try it