I installed louvered vents in my bin door that houses the gen and no more issues. I used basic white floor vents and it looks factory.
With all the issues these have with overheating to me it's a design flaw. Why manufacturers continue to put gens with little ventilation directly behind the motor and headers is beyond me. It's literally the worst place you could put it - or the best place if you are trying to get overheat shut downs as frequently as possible. I seriously think some of these engineers have never spent a day in an RV.