No, most Mercury outboards do not come with an hour meter from the factory. You would need to install an aftermarket hour meter to track engine run time. These are readily available and simple to connect, typically to a spark plug wire or directly to the battery.
Yes, many boat owners can install an hour meter on their Mercury outboard themselves, especially if it's an inductive type that simply wraps around a spark plug wire. For wired models, basic electrical knowledge and adherence to the installation instructions are key. If you're uncomfortable with electrical work or unsure about any steps, it's always best to consult a qualified marine technician to ensure a safe and correct installation, protecting your engine.