Where is the 'o' ring in the CV carbs? -- Flat at WOT

[smoketriples]

I see a reference to an O ring discussed in the CV carbs needle jet, but I've torn mine down and can't find where these O rings are supposed to be.

Looked at the pinkpossum exploded view (very nice), but nothing on this O ring. Is it on the flange of the needle jet where it pushes into the upper carb body?......

Spent a good deal of time rebuilding these carbs (bike sat for 15 years with gas in it). Bike starts great and runs okay but is very flat when it should be on the pipe. 5k RPM in top gear and going to WOT gets a big change in intake sound but no corresponding jump on the pipe. Revs up nicely out of gear but really lacks power in gear. Timing is dead on with a genuwine suzuki dial gauge.

It is running cheap pods and 3 - 3 chambers, so my stock 110 jets are likely not correct, but I have to wonder about the O rings since i never saw them and I stripped these completely down before soaking including removing the long needle jet.

Taking the carbs off tonight to put bigger main jets in (going to 120, and raising needle a notch, unless someone else has a recommendation for a different start. I have 115, 120, and 130 on hand). Would like to rectify 0 rings as well if someone can tell me where they go, or even better, post pic!!!!!

[Coyote]

I have just been through a set of CV carbs myself. There are no o-rings. VM carbs used a small o-ring on the air screw, but BS carbs do not use them.

[tz375]

O ring part number 09280-03003 fits around the top of the needle jet where it presses into the carb body. They are very small and after years of neglect they look more like a thin film of something.

For some odd reason I can't upload a file today. send me your email address and I'll mail a picture of the needle jet and the O rings

[oldjapanesebikes]

On the fiche listings its item #26 - see below. There are also o-rings on the pivot shafts for the butterfly - they are not listed as a part number, but can also be replaced if you can find the right size.

[smoketriples]

Ah perfect there it is. I have to clean out that idle circuit too, middle cylinder isn't firing at idle .

[Coyote]

I didn't remove the needle jets nor the butterflies. I guess that's why I didn't see any o-rings.
And by the way, what's the difference between a needle jet and a breader pipe?

[tz375]

Breeder pipe? I haven't come across that one. Where is that reference Chris?

BTW, the Carb manual shows that O ring on P12.

Old style bowl gaskets had a hole for the pilot jet on one side only and it's possible to block off that jet if the gasket is flipped over. I think that later gaskets and Keysters have a pair of holes to eliminate that issue, but it's worth a check.

When cleaning BS carbs, pay attention to the tiny air passages. The main air jet is only 1.0mm and the pilot air jet is 0.5mm. Make sure it is clear and that you can blast air or cleaner through to the mixing chamber.

The other one to watch for is that tiny starter jet in the bottom of the float bowl. That's clogged as often as not.

[Coyote]

Go to: http://motorcitypowersports.com/catalog.asp" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false; and click on the oem icon. select motorcycles, Suzuki, 1978. GS1000C. What appears to the needle valve is called a breader pipe.

[oldjapanesebikes]

Hmmmmmmm...........I'm thinking typo. Should be 'breather' eh ?

[smoketriples]

Yeh I'm a dirty old man so I see breeder pipe and I think of something completely different

[tz375]

Ian is probably right that they were describing teh fact that it mixes air in with teh fuel hence Breather pipe or Breader.....

It's also known as a nozzle in cars

[oldjapanesebikes]

Just for info - Reiner sells the v seal style o-rings for the throttle shafts under his part number 13354-31210-000-Z, at €2.70 (about $3.86 in USD) each for non-EU buyers plus shipping of course. Six required.

[Coyote]

Sooooooo, Is the breather pipe the needle jet?

[rbond]

In the case of the GS1000C carb, yes the 'breader' pipe is the needle jet. Where they got that name I have no idea.