I would do a complete service; all filters, new fuel and plugs and then see if it still gives a problem. You did not say how many hours are on the genset and if you have been running it regularly; not allowing fuel to go bad in the carburetor.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7