My Mini Dirt Bike Keeps Cutting Out?

Hi, When i start my mini dirt bike its fine, when i start riding around it keeps on cutting out and its not because the choke or anything is off/on, i have cleaned the spark plug and fiddled around with the carberetter.i was just going to buy a new carb. can some one help me please?

email me if you can : narlow123@hotmail.com