Topic: Two dumb carburetor questions.. PD46C 1978 CB550K

[kweb]

I have a 78 CB550K with the PD46C Carb's on them. I reassembled them and they leaked like crazy. I've disassembled them again to thoroughly clean them up and have two dumb questions. The first is the fuel line from the tank. Does it attach to the larger brass orifice which looks like it feeds the carb rack? Is the smaller one a vent? I've attached a picture of the #2 Carb body with these ports. The second question is where can I find gaskets for the fuel rail tubes? I've also attached pictures of that as well.

When I hook up the fuel line to the larger of the brass fittings fuel leaks from the rail tubes. When I attach it to the smaller brass fitting it leaks from the overflows on carbs 1 & 2.

I'm so frustrated because I am so close to getting this bike back together!

[kweb]

Here is the picture of the fuel rail tube gaskets.

[harisuluv]

You are correct the larger one is for the fuel.  The other one is for the air vent as you were suspecting.  Looks like you are reusing the old o-rings for the fuel connector, seems to be about the same diameter as the aluminum so you are not getting much sealing with that. 

The o-ring is about ID:  6mm Diameter and 2mm thickness.

Try harbor freight they have an o-ring kit that is real close or a hardware store.  Make sure they are nitrile if viton is not available.

[kweb]

My suspicions were correct then... I'm an idiot. Thanks so much for the reply. I'm definetly not getting any sealing with these old orings. I don't know how the carbs weren't leaking like crazy before I took them apart in the first place. Thanks again...

[harisuluv]

When they are in there awhile they kind of bond cleanly and harden in that state, but taking them out will break that seal. 

[lucky]

Here is the picture of the fuel rail tube gaskets.

Those are not gaskets. They are O rings.

[liPPy]

Here is the picture of the fuel rail tube gaskets.

Those are not gaskets. They are O rings.

[kweb]

Wow! You have way too much time on your hands... Thanks for the information though.... really, thanks.

[bollingball]

Here is the picture of the fuel rail tube gaskets.

Those are not gaskets. They are O rings.

 

[cgswss]

You can also use common "dash size o-rings"

Fuel rail takes "-010" o-rings

-007 Accel pump O-rings