How to tell if a chain is Bicycle Chain or something else? Hello is there anyone that is able to help me?  I need to get a new chain for my little boy's quad bike and I'm unsure on what size I need to get.

Its a 50cc mini motor quad bike. I have looked online but says all different numbers of links and the one that is on it already is too small as I bought it off some bloke who didn't have a clue what he was doing.
From a little research it would appear most Mini Moto Bikes &amp; Quads up to 50cc mostly use a 25H or 25E chain. 
They vary in price depending on retailer but most seem quite easy to buy being a popular item. As we know very little else regarding main drive dimensions (cog / gearing) apart from the fact it should only consist of a main drive gear and a smaller one on the rear axle. 

All I can do is attach a chart of the most likely chains and the OP can hopefully work out what chain is required according to the dimensions on the gearing.