How do I install a pocket bike gas gauge on a pocket bike?

[cooldude14]

Hi I have a 49cc pocket bike and I want to install a gas gauge on it. How do I install one? Do I need something to make it work, and I found a gas gauge thats especially for pocket bikes on this website http://www.pocketbikeparts.com/Speedometer_p/krsd302498.htm. Plz help me!