Quick CU Carb Fin
One of the joys (or pitfalls if you're stranded on the side of the road) of having a bike that's a little older than the modern Twin Cam is that it typically requires a little more attention to ensure it stays running. Of course regular maintenance and upkeep is necessary to make sure any bike is running at its best, but no matter what you do, some things are just going to break, fail, or not quite work like they should. We recently ran into a situation such as this when finishing up some final details on one of our project bikes, a '96 Springer.
We had just installed a different gas tank and a new petcock, but when we turned the fuel on and began trying to start the bike, we noticed that fuel was dripping down onto the floor. After flipping the petcock back to the off position we kneeled down to inspect the carb, and noticed that the fuel was dripping from the left side. Thinking that the fuel inlet hose was cracked, we loosened the hose clamp and as we wiggled the hose to pull it off the inlet valve, we noticed that the fuel dripped more steadily. It was then that we noticed that plastic inlet valve on the stock CV carb was cracked. Nothing too unexpected, seeing how it is a plastic piece that has been exposed to sun, fuel, vibration, and who knows what other abuse and gets brittle over the years.
The thing is, you can't just unscrew the plastic piece to replace it. The plastic elbow resides on a brass fitting that is pressed into the side of the carb. While some people have just broken off the plastic valve and run the fuel line directly onto the brass fitting, the proper way to fix the situation is to install a new valve. Like they say, there's more than one way to skin a cat, so we decided to take some pics and show how we did the procedure. An important thing to remember is, if the inlet valve hasn't already broken off of the brass fitting, before you remove it, take a mental note (or make a mark) of its position so you orientate the new fitting in the same manner. HB
To help keep debris from entering the carb we secured the it in a vice with the fitting facing downward. We then used the 1/2-20 tap and threaded it into the brass fitting almost a 1/2 inch. It's important to be very careful and not go too deep because you don't want to muck up the carb body.
As we removed the fuel inlet hose from the valve, the valve broke into pieces, so we pieced it back together so you could see the original crack (arrow).
Was this article helpful?