I have a 2004 Scrambler 500 and my carb started to leak from the drain plug about a month ago. I bought a kit for it, including the needle,seat,and all the gaskets. i replaced everything and it stopped leaking but after 1 ride it started to leak from the overflow. any suggestions???? I don't know what to do.

 

Common problem on the BST40 carb. Just the way the float bowl itself puts pressure on the needle valve to seal it down to the carb body along with the float system in general. I've tried different metric o-rings around the valve,adjusted the tang on the float every which way,but still will leak out the overflow after awhile. The old BST 34 never had this problem. Usually they leak while idling, not to much while riding. I would just add an extra length of drain tube to drain down under the bash plate at least to keep gas off the engine and exhaust area. I wouldn't plug the line up.I have heard of people that have sealed off (soldered) the drain tube opening in the float bowl,but this just will allow extra fuel in the engine at idle. OPT