Look on the clutch side (Side that says Yamaha on the engine) just have where it says yamaha you'll see the little screw cap thing where the oil goes in. ... I always ran ATF (automatic transmission fluid) in my blasters.. purely because when I first asked about doing an oil changed that's what I was told to run by someone on here... NEVER had a problem! oh also if you're wandering.. They take 650ml
the screw to drain the oil is under the motor and i can not get the screw off to change it its been the same oil for over a year but the cap has oil on it and is stripped