You can prove it's fuel by shooting some carb cleaner in the air breather. If it fires you most likely have a fuel delivery problem. You did confirm the tank has fuel didn't you or that the petcock if it has one is turned to the proper position?
If you don't hear the fuel pump prime when you turn the key on, then that's likely the issue. Just recently had to replace mine in a Chinese UTV we have. Never occurred to me that I wasn't hearing it. Crazy thing is, when I took it to the dealer to ask if they could test it, they said there was no way they had to do it, had to be on the machine. I finally got to talk to their wrench and he simply unplugged the connector on another machine and plugged mine in. Hit the key and zip, zilch, nada. $120+ later and it's running again. And they say Chinese parts are cheap???? ? ?