What oil do you use on a 2000 Yamaha big bear 4x4?

For a 2000 Yamaha Big Bear 4x4, it's recommended to use SAE 10W-40 motor oil for the engine. Additionally, you should use a high-quality oil that meets the API service classification SG or higher. For the final drive, Yamaha recommends using a hypoid gear oil with a viscosity of 80W-90. Always refer to the owner's manual for specific oil recommendations.