Things You'll Need
Oil cap O-ring
Oil drain pan
10 and 17 mm sockets
Oil drain plug O-rings
5 mm Allen wrench
Regular oil changes are a necessity for all of Yamaha's four-stroke all-terrain-vehicle models. Although each model may have its own requirements, the basic process of draining the engine oil through a drain plug built into the engine crankcase and replacing the oil filter is similar throughout. In addition to the crankcase oil drain plug, some models — the Raptor and YFZ450, for example — use an external oil tank and have a second drain plug. You must be familiar with the location of the ATV's oil drain plugs and the oil filter before beginning.
Warm the ATV's engine and oil supply. Start the ATV and let it idle for 3 minutes, then stop the engine and let it cool for another 10 minutes.
Remove the plastic engine covers, if any, from both sides of the ATV. Pull the bosses on the upper edge of the cover, near the ATV's seat, out of the grommets built into the ATV's frame. Pull the covers toward the rear of the ATV until the tabs at the front of the cover are free from the front fender.
Unscrew the oil cap from the top of the right engine crankcase cover. Wipe the cap's attached dipstick clean with a shop towel. Inspect the oil cap O-ring for damage. Replace the O-ring if it is torn or frayed.
Place an oil drain pan beneath the engine crankcase drain plug, located either directly under or along the left side of the crankcase. Unscrew the drain plug, using a 17 mm socket and a socket wrench. Drain the engine oil into your drain pan.
Unscrew the oil tank drain plug from the bottom of the oil tank, located behind the engine, using a 17 mm socket and a socket wrench. Drain the engine oil into your drain pan. Skip this step if your ATV is not equipped with an oil tank.
Remove the gasket or O-ring from the drain plug, then wipe the plug's threads with a shop towel. Slip a new O-ring or gasket onto the drain plug, then screw the plug into the crankcase by hand. Tighten the drain plug to 17 foot-pounds, using a 17 mm socket and a torque wrench. Reinstall the oil tank drain plug, if applicable, using the same method.
Remove the oil filter from the right side of the engine. Use a cap-type filter wrench to remove a spin-on-type oil filter. If the ATV uses an internal filter element, unscrew the oil filter cover from the right engine crankcase cover with a 10 mm socket or a 5 mm Allen wrench. Pull the cover, oil filter spring and the oil filter off of the engine. Wipe up any remaining oil with a shop towel.
Install the new oil filter into the engine. Spread fresh engine oil around the filter's sealing O-rings. If you are installing a spin-on filter, screw it into place by hand until it is seated firmly against the engine. Alternatively, push the internal oil filter into the engine, followed by the oil filter spring and the oil filter cover. Screw the oil filter cover bolts into place, using a 10 mm socket or a 5 mm Allen wrench. Tighten the bolts to 7.6 foot-pounds, using a torque wrench.
Place a funnel into the engine's filler neck, located on top of the right engine crankcase cover. Fill the engine with the amount and type of engine oil specified in your ATV's owner's manual. Screw the oil cap into place by hand.
Fill the oil tank with the amount and type of engine oil specified in your ATV's owner's manual. Screw the oil cap into place by hand. Skip this step if your ATV does not have an external oil tank
Start the ATV and let it idle in place for 3 minutes. Watch for leaks at the oil drain plugs and the oil filter or oil filter cover. If a leak appears, tighten the affected part an additional quarter-turn. Stop the engine.
Unscrew the oil cap, then wipe the dipstick clean with a shop towel. Insert the dipstick into the oil tank or engine until the cap's threads are resting on the oil filler neck. Pull the dipstick out and check the oil level. If the oil level is below the dipstick's lower mark, pour 1 to 2 oz. of engine oil into the oil tank or the engine. Recheck the oil level. Screw the oil cap into place, if the oil level is above the lower mark.
Reinstall both plastic engine covers. Slide the tabs on the front of the covers into the slots cut into the front fender. Push the bosses on the upper edges of the engine covers into the grommets built into the ATV's frame.
If you don't have the ATV's owner's manual, the engine's maximum oil capacity is usually imprinted into the right engine crankcase cover.
Your Yamaha ATV may require additional steps beyond the procedures shown here. Please refer to a Yamaha factory service manual for detailed instructions specific to your model.