The 2007 Yamaha 115-horsepower outboard has a four-stroke engine. It carries 4.55 quarts of oil in its crankcase and, depending on the filter cartridge used, as much as an additional quart for the filter -- important information to know when you select the container to receive the used oil. Yamaha recommends you change the oil yearly and the filter every two years or 200 hours. Under conditions of heavy wear or use, more frequent changes of both oil and filter become necessary.
Move the outboard to an upright position -- no tilt forward or aft and no tilt side to side -- completely vertical. Unlike some outboards, the crankcase does not drain through the front of the lower unit. This means the motor must not be tilted. Position oil absorbent pads beneath the outboard and place an oil change container with a minimum capacity of six quarts beneath the motor, on top of the pads.
Remove the drain screw, located on the starboard side, near the top of the exhaust tunnel -- the outboard's "leg" -- with a 3/4-inch hex wrench. Remove the oil filler cap and allow the oil to drain down the side of the engine and into the oil change container.
Place an oil-absorbent pad under the oil filter. Unscrew the oil filter container, located on the starboard side of the powerhead, directly beneath the intake manifold. Keep the container upright and dump any oil in the container into the oil change container. Fit the new filter cartridge into the container and screw the container back on to the powerhead.
Install a new gasket on the drain screw, while the oil drains. Apply a light coat of oil to the gasket. When the last of the oil drains, replace the drain screw and tighten it to 20.7 foot-pounds with a torque wrench.
Add 4.3 liters, or 4.55 quarts of 10W 40 oil through the oil filler on the top rear of the motor. Don't overfill the motor, but that 4.55 quarts does not include the oil held in the filter -- plan on 5 quarts. Replace the oil filler plug, tightening it by hand only. Start the motor, and wait for the low oil pressure light to go out. Once the oil pressure light is out, check around the motor for oil leaks.
(See reference 1, p.66)
Turn the motor off and wait three minutes, to allow the oil to settle in the crankcase. Check the oil level with the dipstick, located on the starboard side of the motor, at the bottom of the powerhead -- remove the dipstick, wipe it clean, reinsert it, remove it and inspect it. The optimum oil level lies between the top and bottom marks on the sticks. If all is in order, wash the exterior of the motor with mild detergent and water. Dispose of the used oil properly.
- Never change the oil immediately after you use the motor; it's too easy to get burned by hot oil when you're doing an oil change.
- Disconnect the negative cable of your battery before performing any maintenance work on your outboard motor, to prevent electrical shock or accidental starting. Remove the nut from the negative post with a 5/16-inch box-end wrench. Lift the cable from your battery, move it outside of the battery box and close the lid of the battery box. After the work is complete, reconnect the negative battery cable.
- If you work on your outboard motor when your boat is on its trailer, or your motor is on a storage stand, remove the propeller nut with a wrench and slide the thrust hub, propeller and washers from the propeller shaft. Failure to remove a propeller before operating an outboard out of the water during maintenance or long-term storage is an invitation to a propeller-strike injury, which can maim or kill.
- Never operate your outboard out of the water unless you provide a source of cooling water, whether by connecting a flushing attachment -- sometimes called "earmuffs" because of their resemblance to that winter-wear item -- to a garden hose and placing the "muffs" of the attachment over the cooling water inlets, or immersing the motor in a motor test tub filled with water so that the cooling water inlets are submerged. Do not use the F115's built-in power unit flushing connector, located on the bottom of the cowling, to supply cooling water to the motor as you test it. The flushing connector will not supply sufficient cooling water to run the motor.
- You'll need a torque wrench for many outboard maintenance projects. If a torque wrench isn't part of your tool kit, tighten the screw finger tight and give it another 1/4 or 1/2 turn as a temporary measure. Borrow or buy a torque wrench before your next outing with the motor and and tighten the screw to the correct torque.
- During each tune up, watch for large changes in valve clearance. These represent possible signs of wear. If such changes appear, change the oil more frequently -- Yamaha recommends once a year; change it every three months. If you are using oil other than Yamaha's brand, use a different brand of oil or switch back to the Yamaha brand oil.
- Yamaha F115/LF115 Owner's Manual - USA Edition