I have a customer with an Olympian generator, model G25F1S.
Last year I had an issue with it starting up and immediately overspeeding and then shutting down. I found that the electronic governor control linkage was sticking. Now it starts hard due to low speed and then ramps way up and runs to fast, it pegs the frequency meter.

My question is, anyone know what caused this?? I am going to assume it is the electronic governor, but don't want to assume. Any links to some good troubleshooting charts?

If it is running on gasoline, I think it is time to clean the carb.

No gasoline. It runs on LP gas. It is governor related, however unsure if it is actually the governor that is bad or the controller. I done a service call on this same unit a year ago. At that time the linkage was rusted up and sticking. I cleaned it up and lubed it. It has worked fine since then, until now.

It has been many years since working on generators but, if you can't find much on Olympian, contact the engine manufacturer. Typically the engine speed governor comes with the engine.

If the engine is air cooled, check with Briggs, Kohler, Onan, Tecumsah, Wisconsin, Honda, etc.

If it is water cooled, check with Kohler, Onan, Ford, Winco, etc.

Larry