Yamaha T9.9LMHB v11 Owner's Manual
![Yamaha T9.9LMHB manual cover](/images/d954855971b972b5dd5daa1f/thumbs/thumb175x175.webp)
The recommended fuel type for the Yamaha T9.9LMHB is unleaded gasoline with a minimum octane rating of 87 (Ron+Mon/2) or 91 RON.
Regular maintenance should be performed every 100 hours of operation or at least once a year, whichever comes first. Refer to the owner's manual for detailed maintenance schedules.
To change the engine oil, warm up the engine, stop it, and remove the oil fill cap. Place a container under the engine, remove the drain plug, and drain the oil. Replace the drain plug and fill with recommended oil. Check the oil level and replace the fill cap.
If the engine does not start, check the fuel level, ensure the fuel line is not blocked, inspect the spark plug for wear, and verify that the kill switch is not engaged.
The recommended spark plug for the Yamaha T9.9LMHB is NGK BR6HS. Ensure it is properly gapped and installed.
For winter storage, drain the fuel, fog the engine, change the oil, and store it in a dry place. Remove the battery and store it separately, and cover the outboard motor to protect it from dust and moisture.
If the engine overheats, stop it immediately and let it cool down. Check for water flow from the cooling system, inspect the water pump, and ensure the water intake is not blocked.
To improve fuel efficiency, ensure the engine is well-maintained, use the correct propeller size, avoid excessive idling, and operate at optimal cruising speeds.
The correct propeller size can vary depending on the specific application, but the standard propeller is typically 7 1/4 x 5 1/2 inches. Consult the owner's manual or a Yamaha dealer for recommendations.
To adjust the idle speed, locate the idle adjustment screw on the carburetor, and turn it clockwise to increase the speed or counterclockwise to decrease it. Ensure the engine is warm and in neutral while making adjustments.