Pull the engine cowling and see if there is a oil reservoir (like a plastic tank). Usually located on the port side of motor. If there is no plastic tank, then YOU need to add oil to the fuel.
Could vary with motor manufactures. 50:1(2.6 ounces/gallon) is the most used and widely accepted fuel/oil ratio. However, it may be best to contact yamaha and verify.Do you know what the ratio of oil to fuel is? How many parts oil to gas it has to be for the 60hp Yamaha model year 2000.