have a question! cany anyone tell me if this carburetor is compatible with the B&W250 carburetor?
thank you- 
30MM CARBURETOR CARB GY6 250CC GO KART SCOOTER ATV
No. I went down the aftermarket carb path. On 50cc to ~150cc scooters there are lots of aftermarket choices. For the Kymco GV250 you could use and aftermarket but you would need to modify things quite a bit and I don't think it is worth the effort. You can get the OEM carb online as cheap as ~ $235 to $250. I have a spare OEM carb if you need a particular part.
Here's some reference videos:
Carburetor Cleaning Part I
http://youtu.be/w4vW4zh8g0QCarburetor Cleaning Part II
http://youtu.be/ig0qHhdxJFECarburetor Cleaning Part III
http://youtu.be/EjCmiZ5xoeUKymco Carburetor Remove & Reinstall
http://youtu.be/uE3d9QI2m2Y
