How i can pump the weels on the back - Razor E200/300 Electric Scooter Battery

Hi, you need to take the end-cap off of the right side of the handle bar. It is a black cap/plug that pulls out. You will see a black plastic piece that's about 3" long. Pull that out of the end cap. This is the extension that is screwed on the the air valve. Just place through the hole in the rear sprocket and thread on, and fill the tire with air. When done, unthread it and replace back into handle-bar end-cap and reinstall the end-cap. It only took me 4years to figure that out!