Topic: cb 550 carb needle holder issues

[Boost_Junkiee]

Ok, So I got my rebuild kits yesterday and I was cleaning the items I was going to reuse i.e. the needle holders, when I noticed one of the needle holders (as the keihin carb article states thats what they are called) has tapered holes in it getting smaller as it gets to the top but my other 3 needle holders have the same size holes all they way up. If you are confused as to what I am talking about it is the brass straw looking peice with holes in it that press into the carb body where the needle passes thorugh. SO my question is that are all those needle holders supposed to be the same? with the same sized holes or is one supposed to be different and if so which carb is it supposed to go to? please help! my carbs are the 74-76 carb style the o89a's I believe. Thanks for any help!

[Gordon]

I can't say for certain, as I don't have them in front of me to look at, but I seem to remember mine being all the same size.  Regardless, they should all look the same, so something is amiss.  Does the odd-ball have any other type of markings that distinguish it from the others? 

Other names for it are "emulsion tube", and "needle jet". 

[Boost_Junkiee]

I am guessing the previous owner mixed and matched carb parts from another carb? I figuired they should all be the same size but I wasnt sure and I could find no info stating one should be different. There are no distinguishing markings except the hole sizes being different. They fit in the carb the same as the others also...

[Gordon]

Hmm...  Hopefully somebody else who either has their carbs apart or knows for sure which ones are correct will chime in, but chances are the odd-ball is the incorrect one. 

Thinking ahead, you may want to post in the parts wanted section to find a replacement.  IME, the emulsion tubes are not readily available, so if you can't find a good used set from someone you may need to find a used set of carbs that contain them. 

Another option is to find the instruction on this website from Hondaman about improving the performance of the 550.  If I remember correctly, he includes detailed instructions on enlarging the size of the stock emulsion tube holes and possibly adding new holes.  If you did this procedure then I would imagine that the current difference in hole sizes wouldn't matter anymore.   

[05c50]

All the emulsion tubes that I have seen have had the same size holes the whole way up. If you replace the odd one, make sure that the inside diameter is the same as the rest. I had a problem with the diameter being too large and causing an over rich condition.

........Paul

[Boost_Junkiee]

Cool, thanks for the help! I actualy have a second set of carbs but I was hesitant to take them apart. I guess I will use another emulsion tube from that set and take them all out see if they are the same. I guess I could have done that in the first place