Yamaha F150DETX v6 Owner's Manual

The recommended maintenance schedule includes checking the engine oil and lower unit oil every 100 hours or annually, inspecting and replacing the spark plugs every 300 hours, and changing the fuel filter annually. Regularly consult the owner’s manual for a detailed maintenance plan.
If the engine does not start, check the battery connections for corrosion and ensure they are tight. Verify the fuel system for any obstructions and confirm that the fuel is fresh. Inspect the spark plugs for wear and replace if necessary.
Use Yamalube 4M FC-W® 10W-30 or 20W-40 oil, which are specifically formulated for Yamaha outboards. This ensures optimal performance and longevity of your engine.
Rinse the outboard with fresh water after each use in saltwater. Apply a corrosion protection spray on the engine and any exposed metal parts, and regularly inspect anodes, replacing them if worn.
First, shut off the engine immediately. Check for any blockages in the water intake and remove debris. Inspect the water pump and impeller for damage and replace if necessary. Ensure the cooling system is functioning properly before restarting.
To winterize, add a fuel stabilizer to the tank, run the engine to circulate the stabilizer, change the engine and lower unit oil, and fog the cylinders with fogging oil. Store in a dry, covered location and disconnect the battery.
The ideal propeller size depends on the boat type and usage. Generally, a 13-1/4 x 17 pitch propeller is common. Consult with a Yamaha dealer to determine the best fit for your specific needs.
Maintain proper engine tuning, ensure the propeller is the correct size and pitch, avoid overloading the boat, and operate at optimal engine RPMs. Regular maintenance and using high-quality fuel also contribute to better efficiency.
Remove the lower unit, disconnect the water pump housing, and replace the impeller and gaskets with new components. Reassemble the water pump housing and reinstall the lower unit. Refer to the service manual for detailed instructions.
Inspect the propeller for damage or balance issues. Check the engine mounts for wear or damage. Ensure there are no obstructions around the lower unit, and verify that the engine alignment is correct.