For every 100 hours of use, the oil in a Yamaha Waverunner should be changed. The process of changing oil in a Waverunner is different from other vehicles because the oil has to be sucked directly out of the engine instead of draining into an oil pan. Begin by warming up the oil by running the engine for a few minutes. Then, place the Waverunner in a horizontal position.
Remove the oil filler cap and insert the oil changer tube. Next, siphon out the old gas into an appropriately sized container (figure enough to hold three quarts of oil). Remove the old oil filter with a wrench, and then install a new oil filter. Add in two and a half quarts of new Waverunner oil. Screw on the oil filler cap and you’re all set!