Topic: please help. . .cb550 main jet keeps on falling. .

[francis8766]

Heeelp. . I just talked to my mechanic regarding my cb550 carbs. . He wants me to replace all 4 carbs because according to him, the carb wall expanded and the main jet keeps on falling off in its place. . Is thereca way to fix this? Does this really happen? I mean, does the carb really expand when it gets soaked in gasoline for a very long time? Thank for your help. . .

[francis8766]

. I just called my mechanic again and he said that the holes where the main jets are inserted expanded thus making the main jet loose. . Should i really replace my carbs? Or is there another way to fix this? Can i use a larger o-ring?

[Gordon]

Your mechanic doesn't know your carbs.  Your main jets need a spring clip to keep them in place.  There is a groove in the body of the jet where the spring clip sits, and the arms of the spring rest on the bottom of the float bowl holding the main jet in place.  They are not easy parts to find, individually, though.  So, often, your best bet is to find an inexpensive set of used carbs for sale that include the spring clip. 

[francis8766]

Thanks for the info good sir  . I will try to look for spring clips . I found an article regarding a makeshift retainer clip for the main jet. . Ill try to do that and also look for it in ebay. Thanks again

[LesterPiglet]

If you can't find any.

http://forums.sohc4.net/index.php?topic=101803.0;topicseen

[ekpent]

Those also should have a rubber o-ring that when new should help hold them also along with the mentioned leaf clip.

[Bootlegger56]

If the bores of the jet holders are ate up / enlarged you could also opt for an o-ring with a thicker cross section to aid in making up some of the difference.  The stock is 1.2mm wall thickness (cross section).  Perhaps a 1.3 or up will help the problem as well.  I would do the e-clip/spring trick if I were missing the jet clips.   

[Raul CB750K1]

In my cb350 I found out one of the idle passages was obstructed due to a broken screw, so I had to replace carb bodies.

I had brand new jets, floats, whatever, so I bought a set of carb bodies making sure the idle passages were unobstructed beforehand.

Much to my surprise, one of the emulsion tubes won't fit. It would simply fall off. I couldn't see any damage in the carb body but the emulsion tube kept falling.

I ended up aplying a little solder to "thicken" the emulsion tube so it would stay in place.

Don´t know if that's what your mechanic is talking about.


(on an unrelated note, changing the carbs didn't fix my erratic idle problem in the CB350 twin)

[Kbecker]

http://www.siriusconinc.com/pro-detail.php?pid=&product_id=120437

[harisuluv]

Yeah I bought several SETS of those siriusconinc leaf springs.  If you look at the pictures, you'll notice they aren't shown at all at the reverse angle, and there's a reason for that.  Every single one is cracked on the tang.


I make my own now, and they are the most accurate currently on the market, for $40 shipped.

[grcamna2]

Those springs of yours are beaut's harisuluv,are they as good if not stronger than OE ? will they also work on CB350 twin 722A carbs ?

[harisuluv]

Thank you, it took me many tries and experimenting to get them right.

They are comparable to originals.  I used a specific type of steel that was closest to OEM, had them waterjet cut, deburred, hand bent them all (the tang that is cracked on the other springs was not even bent to 90 degrees, probably because they knew it would break if they did, which is how i mine), heat treated, then corrosion treated them to the same finish as originals.

The cb350 twin ones i think might be slightly different shape for the bowl, however I sent one that was a spare to a member and he was able to make it work.

[dave500]

excellent work harisuluv.