What is the best carb to buy off ebay for a 200x? My stock carb is leaking gas like crazy and back firing when you let off the gas and there is white smoke coming from exhaust and spark plug is black. I think I may have turned the pilot screw to tight and damaged the seat. Is there a way you can tell if the seat is damaged? I dont know if I should rebuild the stock carb or just buy an after market one off of ebay. The rebuild kits are haft the price of a new carb and im not a carb expert and not sure if the seat is damaged. What is the best carb to get off of ebay and the biggest one I can get without having to modify the intake.