what brand of pumper carb, what size [250cc still with BG \airbox\jetted] where to buy, and how much?

 

What, you want one of us to decide for you?

Go to the KLX section of Thumpertalk.com were you can search-out and read several informative threads on the subject. There's also some good material over at planetklx. Sounds like you might be in the market for a TM-33 if you will be running 250cc. Also talk to Marty at klrworld.com. He has a TM-33 and some good contact info for someone who can make it fit well without modding the frame.