The solenoid on your ATV is used to start the vehicle. When the solenoid is turned with the ignition key, electricity is able to flow through the solenoid to the starter. If you can't get your ATV to start, you can test the solenoid with a few items found around your home. You don't have to be an ATV technician to test your solenoid. You can do it yourself with little hassle.
Turn the ATV off. Go to the handle bars and locate the solenoid cable. This is coming off of the handle bars next to the "On" switch. Follow the cable all the way down to the engine underneath the seat.
Use a voltmeter to get a reading on the battery. Connect the red wire from the voltmeter to the red terminal on your ATV battery. Touch the black wire from your voltmeter to the black terminal on the battery. ATVs use 12V batteries. If you get a reading that is not 12 volts, replace the battery.
Connect the red lead to the solenoid wire coil while keeping the black lead on the black terminal of the battery. Wait for the reading. You should see a 12V reading on the voltmeter. If you do not get 12V on the voltmeter, your solenoid needs to be replaced.