Onan Running Problems

My generator would run for a while, like yours, then shut down and not want to start again until it cooled. I am no mechanic so I can't give advice, but an RV mechanic gave me a tip. On the oil dipstick there is a full mark and a low mark. Generally, the tendency might be to keep the oil level up near the full mark. However, generator oil gets extremely hot and (I assume) expands. The mechanic told me that I should keep the oil level a bit lower toward the fill line allowing the oil room to expand. Of course, if you do that you should check your oil frequently to be sure it doesn't fall too low. Anyway, it worked for me.