bought a 2008 baja 250cc that was only used a handful of times.
changed the oil, cleaned the carb, flushed the fuel, new fuel filter, new spark plug and new battery. won't stay running unless choke is engaged. as soon as you hit the throttle it turns off. i've done pretty much everything possible so i'm at a loss. any ideas would be greatly appreciated.

 

If it needs choke all the time, it isn't getting enough fuel through the jets, or it is getting too much air. So you either still have a blocked jet, or the float level is to low, or air is getting into the inlet manifold.