anatomy of a carb

In image 1, what are the brass colored vertical tubes called? I can't find a part name or reference to it in the shop manual.

Notice in image 2 how the end of the smaller diameter tube is pressed against the outside of the larger diameter tube.

In image 3, you can kind of see how the smaller tube is pressed against the outside of the top of the larger tube.

If you could see the vertical tubes from the side instead of the front or back, you would see that the smaller tube is pressed against the opposite side of the larger tube at the top than it is at the bottom. Image 4 is an exaggerated drawing of this (red box represents outside larger diameter tube and black lines represent smaller inside tube).

Is that normal? Or are those tubes warped?

Re: anatomy of a carb

the smaller one is for idle/lowspeed fuel.
the larger one is the main jet emulsion tube and carrys the fuel at high speeds, it also has some holes drilled in it.
this allows a certain amount of air to mix with the fuel, hence the term emulsion.

Re: anatomy of a carb

They ARE bent in that manner from the factory.

Don't ask me why.

It could be their method of keeping them in place without vibrating and wearing during operation. (Sounds like a reasonable explanation).

Just a wild ***** guess.

Re: anatomy of a carb

See the edited picture below, the idle tube is designed to be 'bowed" and must touch inside of main nozzle. Be careful when reistalling throttle plate so it doesnt bind and restake screws to keep engine from injesting them...

Re: anatomy of a carb

Thanks for the replies! Very helpful!

Re: anatomy of a carb

How do you take it out? Push it down into the bowl? I might need to replace mine, too.

Re: anatomy of a carb

I believe that they unscrew from the bottom.

Re: anatomy of a carb

1946Zephyr said:

I believe that they unscrew from the bottom.

Click to expand...

Thanks but outer larger tube is not slotted to unscrew. Inner tube is too small to do anything. Do I use needle nose or something to turn them?