I have just purchased a 1998 Yamaha Waverunner XL760 and im wondering is there engine oil required besides the 2stroke oil that mixes with the gas. When I start the ski the guage shows half full and sometimes it beeps before i try to start it and says low oil. I noticed theres an oil nipple infront of the motor would that be where engine oil is needed to be fill in? if this ski needs oil???