Does a gas powered log splitter require a fixed throttle engine or a engine with a governor?

Log splitter engines run best at high speed. They still require a governor like most small engines, so they can compensate for the load. Engine w/o governor system will stall under load.

Doesn’t matter if it has a throttle or not. It has to have a governor. It protects the engine from over speed and keeps the rpms more constant under load. As an example, my chipper/shredder has a throttle even though it is recommened to run it at full speed on the other hand my generator doesn’t. It runs at a predetermined rpm but both have governors.