1. Make sure the engine is warm so that the oil can drain easily.
2. Place a drain pan below the oil drain bolt, which is located on the bottom of the engine case.
3. Loosen the oil drain bolt using a 17mm wrench.
4. Allow the oil to drain completely.
5. Replace the oil drain bolt, and tighten it to 18 ft/lbs.
6. Use a funnel to add new oil to the engine.
7. The CRF150R requires .75 quarts of 10W-40 oil.
8. Check the oil level using the sight glass on the side of the engine case. The oil level should be between the two marks on the sight glass.
9. Start the engine and let it run for a few minutes. Then turn off the engine and check the oil level again.
10. Add more oil if necessary.
