How do I know if I have VM29 Carbs?

[bucketsofgs1000]

I have searched and found a lot of useful information but here is my dilemma:

-My carbs are off an old 79 gs1000 built out of spare race bike parts.
-They have angled drain plugs (like early VM29's)
-They have vacuum spigots (unlike VM29's from what I read)
-They have brass slides but foam double floats (Y but N)
-They have float bowl overflow spigots (N)
-THEY HAVE 29mm OUTLETS TO THE INTAKE BOOTS (Y?)
-They have a centrally located fuel tee (Y)
-They are the GS and not KZ style carbs (Y)
-They don't have the little box near the air screw next to the float bowl (N)
-They have only three small air holes inside the inlets (N) I think the 29's have 5 or so.

Could these carbs be VM29's? What is really distinctive about these and aren't there also VM28's that are not smoothbores? Maybe that is what I have and the outlet happens to also be 29mm. By the way, where is the 29mm measurement supposed to be (the slide is much bigger than 29, the intake is also)?

Thanks,

-Zack

[Guy]

Don't know about your carbs, but with the cv type, it's the internal diameter of the output of the carb in mm. Hope that helps.

[bucketsofgs1000]

That is what I thought, and that is really why I am confused. The ID of the outlets is 29mm. But I spoke to the previous owner and he said they were stock carbs, so I am pretty sure they are not the smoothbores. Thanks.

[SqDancerLynn1]

The 29mm smooth bores have a large nut on the bottom of the float bowl
to allow jet changes. Other wise they are 26mm Their are a rare few with 28mm carbs, over sea's models ???. The 28 mm are more common on Kawaski

[robinjo]

It should look like this

[img]http://groups.msn.com/_Secure/0TwARA!4W7Hk0BEzBZ!dSah89tqv3vqR*3k5gqkUyCR3BsF!ak T*swL*c4tFYBTn!xtIb4B2UBmRZIE4QI!ng9XmxDk3CgOBzjpg zrtRZ9Clroe!THIMw3g/IMGP0674.JPG[/img]

(Thank you Sharpy for the pic)

If they are VM28's, which are still bloody rare, it is not near as smooth.



These were stock on my '79 1000S, I have the 29's on it now.

And the size of the venturi determines the carb size, it is the narrowest part of the carb, I believe venturi actually means something along those lines, maybe you have VM33 Smoothbores! =P~ =P~ =P~

[bucketsofgs1000]

They are nice and smooth as far as surface finish inside. Also the bore is constant through the entire length from inlet to outlet (bigger at the slide of course). I did read on a link I dug up on this site that early 29s had the angled drain plug on the bottom (at least on the Kawis). I wish I had a digital camera to post some pictures, but I don't.

One thing to note: On all the 29 pictures I have seen there are many air jets on the inlet side (5 or so), while mine only have two on the bottom and one on the starboard side at the inlet. Perhaps I have the 28's. I'll re-measure a bunch of parts and get back to everyone.

Thanks for all the help with this.

[bucketsofgs1000]

Okay, I went back and re-measured them. Oops.... They have an outlet ID of 26.67mm, inlet of 39.89mm, and slide diameter of 31.75mm. So, unfortunately it looks like they are VM26's after all. Oh well. But thank you very much for all the help on my mis-measured confusion.

-Zack

[dardoonk]

29 smoothbores won't have an overflow tube in the float chamber & do not have fuel adjustment screws on the underside like the VM26 does.