Hi,
It won't be a governor as such. The unit will have a rev limiter built into the ignition module if it is non EFI or built into the ECM if it is EFI. I am not aware of any way to over-ride that. More importantly, I don't recommend it. Max RPM is there to protect not only the engine, but also the drive system. With the engine, everything related to power output with fuel delivery and spark is designed to be optimal without going above that RPM. You won't see any great power increase unless you are completely redesigning the engine.
Hope that answers your question.
Matt
Marine Trades Instructor
Marine TQ, Commercial Transport IP, Master Technician, Instructor, 25 years experience