how long has it been sitting there? if so the engine probably flooded since thats a common thing to carbed bikes. what u want to do is leave the key in OFF position and open the throttle all the way and hold it there for few mins (the longer the better chance of getting it start) and don't let go then with ur other hang turn the key in the ignition into ON position and press the starter button to turn on the bike while holding the throttle open. u should see some smokes and stuff if the engine is flooded. my own technique is duck tape the throttle open and leave it overnight. hope this help if not ,oh well i tried.