How Much Oil?

• The 1999 Yamaha YZ400F has an oil capacity of 1600 cc. Check the oil level when the bike is warm to get an accurate reading. Add oil a little bit at a time until it reaches the full level. If you are filling from empty, you will add about 1600 cc of oil. Never run the bike without oil in the tank.
  
  

What Type of Oil?

• Make sure you select the right type of oil for your 1999 Yamaha YZ400F. The YZ400F has a four-stroke engine, so use 10W-40 motorcycle oil, or some other type of oil that specifies it is compatible with your bike.
  
  

How Often to Change?

• How often you need to change the oil in your 1999 Yamaha YZ400F depends on your riding style. In general, you should change the oil after every five to 10 hours of riding, or after every two or three races. Change the filter every other time you change the oil.