To start an ATV, ensure that your four-wheeler is pointed in a safe direction. Then, shift the transmission into Neutral or Park, and engage the parking brake. Now, turn on its fuel valve, and set the engine's ignition stop-switch to the ON or RUN position. Should the engine be cold, remember to set the choke to the ON position, as well. Give it a bit of time for the engine to warm up. Once you're ready, apply the handbrake and release the parking brake. Finally, shift into 1st gear. When you've done that, slowly release its handbrake and gently apply the throttle until it's going at the desired speed.