1. Park the ATV on a level surface and turn off the engine.
2. Locate the transmission fluid sight glass. It is located on the left side of the ATV, near the bottom of the engine.
3. Clean the sight glass with a rag so that you can see the fluid level clearly.
4. Start the engine and let it idle for a few minutes.
5. Look at the fluid level in the sight glass. It should be between the "FULL" and "ADD" marks on the glass.
6. If the fluid level is low, add enough transmission fluid to bring it up to the "FULL" mark. Use a funnel to add the fluid, and be careful not to overfill the transmission.
7. Turn off the engine and check the fluid level again. It should be at the "FULL" mark.
8. If the fluid level is still low, there may be a leak in the transmission. Take the ATV to a qualified mechanic to have it checked.