Thanks for the replies. The extra loads are a possible issue. Would low compression cause this kind of problem?
I first noticed the problem when I had been running down the road for a couple of hours. My refrigerator would have been running and the converter is possible but not likely since the batteries are getting charged by my solar bank and the alternator from the engine. Still it is something to consider. They pulled the Gen set out of the RV to fix a leak between the halves of the case. The oil had leaked down under the generator and mixed with dirt and coated part of the generator. They originally assumed that the generator was overheating because of the oil and dirt caked on it. While they had it out they adjusted the valves. When I got it home I ran it and it started having problems after running for close to 2 hours.