First, I am a newbie to this forum and enjoy reading all about issues. I recently had one happen to me that you all might want to know. I recently purchased a Toy Hauler with an on board Microquiet Onan 4000 generator. The unit would run for about an hour then die and only start and run for 15 minutes at a time after that. I took it in for service and it was diagnosed with a bad fuel pump which they replaced under warranty. They said they ran it for over 8 hours to make sure verything worked fine. I got it back and opened up the Toy Hauler door and ran it for about an hour and same thing happened, it stalled after about an hour. I then took it to another dealer for minor warranty work along with the generator problem. They also said the generator worked fine and nothing was wrong. I then brought the unit back and kept the door closed on the Toy Hauler and everything worked fine. It appears that the generator needs for the door to be closed for proper cooling. With the Toy Hauler door open it appears to over heat. Anybody else experience this???