Topic: CB550 Emulsion tubes.

[Dimitri13]

I'm about to give my 022A carbs (74 550) a thorough clean. I'll be removing the emulsion tubes this time, because I didn't know about them the first time.

I read somewhere in some guide (maybe a HondaMan guide?) that you can do something to them to help atomize the fuel better. Drill out the holes? Drill more? I don't remember and can't find the guide. I also have an air compressor finally, so I'll be able to blow out all the passages properly.

Main reason I'm doing this is because my choke doesn't do what it's supposed to do, and to get the spots I missed the first time.

[goldarrow]

I think emulsion tubes is the name for the rubber air intake tubes, if it is then I don't think you're supposed to drill that. Carb to intake should be air tight...?

[Dimitri13]

The emulsion tube is the brass tube with holes that the jet needle passes through.

[goldarrow]

ok, now i remembered.  i was reading something about that too.  is the goals to increase mpg?  if so, have a look here, might be what you're looking for http://www.sohc4.net/index.php/increasinggasmileage-cb550/

[RAFster122s]

Might take some searching but that info was by Hondaman. It might be covered in the info about the 550 off the main sohc4 pages...worth a look. If someone doesn't post the link here that would be where I would start or look at the threads started by HondaMan.

[phil71]

When you're trying to improve fuel economy on these old bikes , it's best to keep in mind that gas was better and cheaper back then, and the designs reflect that. Short of major cylinder head and cam redesign, you can only push for the highest volumetric efficiency afforded by the original design. Unfortunately for you, that is probably just over 40mpg. Buy a super cub if you want an old bike with insane fuel economy.

[Dimitri13]

Hmm.. I guess I had this mixed up with something.

[phil71]

No, I realize now that someone else mentioned fuel economy. I imagine you just want it to run great.

[Dimitri13]

Yeah, I'd really like this thing to run great A little extra fuel economy would be nice, but I regularly get 39-44mpg, and I'm happy with that.

[becken]

http://forums.sohc4.net/index.php?topic=7401.0
Go through all the posts . I've done the advance springs, drilled emulsion tubes and raised the needle and an getting 46-48 mpg on my 76 cb550f. Bike has never run better.

[Dimitri13]

Thanks becken! That was the thread I was looking for

[Duanob]

I don't think that will fix your 'choke' problems. I would work through that first before modifying the carbs in any way.