Yamaha F2.5SMHA Y12 v2 Owner's Manual
![Yamaha F2.5SMHA Y12 manual cover](/images/2a96ac523e4879f40827e185/thumbs/thumb175x175.webp)
The Yamaha F2.5SMHA Y12 outboard engine is designed to run on regular unleaded gasoline with a minimum octane rating of 86. Ensure the fuel is fresh and free from contaminants.
Regular maintenance should be performed every 100 hours of operation or at least once per year, whichever comes first. This includes checking the oil level, inspecting the spark plug, and examining the fuel system for leaks.
To start the engine, ensure the engine is in neutral, prime the fuel system using the primer bulb, open the throttle slightly, and pull the starter cord briskly. Make sure the choke is engaged if the engine is cold.
If the engine won't start, check the fuel level and quality, ensure the kill switch is in the correct position, inspect the spark plug for fouling, and verify the fuel line connections are secure.
Use Yamalube 4M FC-W 10W-30 or 20W-40 oil for optimal performance. Always check the oil level before each use and top off as necessary.
To winterize, drain the fuel from the tank and carburetor, change the engine oil, fog the engine with a corrosion inhibitor, and store the engine in a dry place. Disconnect the battery if applicable.
Stop the engine immediately if overheating occurs. Check the water intake for blockages, ensure the cooling system is functioning properly, and inspect the impeller for wear or damage.
To improve fuel efficiency, regularly maintain the engine, use the recommended fuel and oil, avoid overloading the boat, and operate the engine at optimal cruising speed.
To change the spark plug, first remove the spark plug cap. Use a spark plug wrench to remove the old plug, check the gap on the new plug, and install it by hand before tightening with the wrench. Replace the spark plug cap securely.
Inspect the propeller for nicks, dents, or bends. Ensure it rotates freely without wobbling. Remove any debris or fishing line from the propeller shaft. Replace the propeller if significant damage is found.