QuestionHi bill, one carb leaks petrol from overflow pipe when petrol tap is turned on, even when bike is running.Do you know how to solve this,thanks.
AnswerPeter, carburetors that have fuel coming from the overflow tube on the bottom of the float bowl are generally having worn float valve needles/seats or some debris has gotten trapped in the sealing area. Turn off the tap, drain the carb bowl at the drain screw and/or remove the fuel bowl retainer CAREFULLY, IF FULL, then keep the bowl level while you remove it and dump the petrol into a bowl or safe container. This will give you a chance to see what kind of materials are in the carburetor bowl. Rust, dirt and water will cause all kinds of problems, sooner or later.
The float is held into the carburetor by a sliding brass pin. If the pin is not stuck, then it should push out easily with the end of a pin or small needle-nose pliers. When the pin is out, the float will drop down, taking the needle with it. Inspect the needle tip for a wear groove and or any debris that may be stuck to it. The seat is screwed into the float bowl and can be removed for replacement or inspection/cleaning. After 30 years, replacement of the parts is the best idea.
The float level is 21.mm which is the point where the fuel valve shuts off the flow, measured from the base of the carb body to the outer edge of the float, when everything is reassembled.
In VERY RARE occasions, the brass tube can have a fracture in it, lengthwise, causing a slow drip, even when the float valve is okay.
http://www.powersportspro.com/partsfish/login.asp will take you to a site that shows illustrations of your bike, but I checked the carb pics and they are VERY light, almost beyond use.
Bill Silver
