Pressing Issues | Quick CV Carb Fix

Tech: DIY

Pressing Issues | Quick CV Carb Fix - Hot Bike Magazine

01. 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).

02. Basically what we needed to do to remove the brass fitting was make a homemade puller. To accomplish this, we gathered a fender washer, deep socket, 1/4-20 bolt and nut, and a 1/4-20 tap.

03. We picked up this new brass inlet valve from our local Harley dealer ($11.95). Being that it's brass and not plastic, this ought to be the last time we have to do this. The valve is press-fit into the carb body, so with a little time in the freezer (right next to the Arm and Hammer), the brass will constrict slightly and make installation easier.

04. 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.

05. We assembled our homemade puller by threading the nut onto the bolt, slid the washer in place followed by the socket, and then screwed the bolt into the brass fitting.

06. We then slowly tightened the nut against the washer. As the nut presses against the washer/socket, the bolt pulls the fitting from the carb.

07. And with a couple of turns, the fitting was out of the carb.

08. After cleaning up with some carb cleaner it was time to press in the new inlet valve. There are a couple of ways to do this, some people heat up the carb body with a small torch to expand the aluminum, some people freeze the inlet valve, and others do both. If you do use heat, it is very important to thoroughly wash the carb body with hot water and soap.

09. As stated earlier, we simply put the valve in the freezer. We then pulled it out of the freezer and aligned it correctly and gently tapped it into position to get it started. We used a C-clamp to slowly press the fitting into the body until it was fully seated. It's important to go slow and not press too hard/far, as you don't want to damage the carb body.

10. A few turns of the clamp handle and the inlet was properly seated.

11. This was a very easy fix to perform, took about a half hour, and the only thing we needed to buy was the new inlet valve. Everything else we had in our toolbox or tub of nuts and bolts.

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.

The Lowdown
Man Hours: **30 Minutes
Aftermarket Parts Used: H-D Fuel Inlet Valve
Total Cost: $11.95


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