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What are they off?

  • Thread starter Thread starter tfb
  • Start date Start date
Its simple. Open the slides wide open and see if there smooth bores and dont have the curved area for the slides. that will end the smoothbore debate
 
they are, without a doubt smoothbores. the small square on the r/h side of the casting gives that away. the bores look very oval, and the walls on the head side look quite thin.
are they a set of 29's bored out to 33's?
they could be a set "played" with by Wiredgeorge. he bores out 26/28's out to 29mm using oval bores. i am currently having a set of 28's bored to 29mm
 
sharpy said:
Its simple. Open the slides wide open and see if there smooth bores and dont have the curved area for the slides. that will end the smoothbore debate
Click to expand...

Correct as usual mate...

i've just been through this with a local with a GS1000ST - like these they measured up at 33 on the engine side but were oval bores.
Suzuki used these nominal 30's on the ST's and some of the rarer 1100's.

JohnKat should be able to identify, he's got a couple of sets of them.
 
Agemax said:
not all smoothbores had the big drain plug, earlier ones didn't. the square casting on the right side of the carbs denotes smoothbores
Click to expand...

So ure saying all smoothies have the square casting, or just the 29's?
 
G'day blokes,

As usual lots of great info. coming up here... have learned more about identifying Mikuni carbs in the last 2 days than in than in the last 10 years. Which may say more about my original level of knowledge than anything. :D
Agemax, I don't think they've been bored out at all; no 'boring' evidence to be seen.

It seems that Mikuni did make 33mm smoothbores; if you go to the Z1 site you can see the stuff that they stock for the "33mm smoothbores".

Well folks, that's been a great help. Nice to be reminded of the Z1 site for parts for these carbs, too... gunna need a few bits and pieces.

Now then, another question. The slender brass 'siphon' that feeds the choke circuit from the bowl on #1 carb has been busted off in the past. Is that something that you guys have ever managed to fix? Or as it's just the one choke circuit on one carb that's affected, would you bother?

Bat on,
Mike.
 
Yes, the local GS1000ST carbs - VM30's with 33 bore on the engine side.....had a broken choke circuit standpipe too. I used a small easyout to remove it - they're only pressed in.
I had a broken set of 29 smoothbores here and the standpipes were similar so I extracted one and gently tapped it into place in the VM30 body...

Oh, and while I think of it, the ST owner put me onto your website when we were talking cam timing. Very useful, thanks.
 
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Hang on, what carbs are they as they are NOT 33 smoothbores. we need a pic of the troat with slides open to see if they are or arent smootbores, thanks
 
sharpy said:
So ure saying all smoothies have the square casting, or just the 29's?
Click to expand...

i am not certain about all the sizes, but 29's DEFINATLY have the square casting, as shown in the pics. they also used both style of float bowls at various times, obviously the easiest way to see is to look through the venturi, they also have shorter slides with the cutouts on the sides and the slide linkage lever at the top are different to normal VM's as well.

TFB, sent a couple of pics to Wiredgeorge, he will identify them correctly for you
 
Agemax said:
i am not certain about all the sizes, but 29's DEFINATLY have the square casting, as shown in the pics. they also used both style of float bowls at various times, obviously the easiest way to see is to look through the venturi, they also have shorter slides with the cutouts on the sides and the slide linkage lever at the top are different to normal VM's as well.

TFB, sent a couple of pics to Wiredgeorge, he will identify them correctly for you
Click to expand...

OK well i have both 29 and 33 smooties and only the 29 has that casting. All i want is a look thru the guts, thats sure fire way to see if they are smoothies
 
Here you go gents. And yes, I do realise that needle will have to be replaced. Cheers, Mike.
 
They be the oval bores that come on the STs and Kiwi 1100 Kats that raced in the proddy races in NZ.
 
Thanks for the identification there Sharpy. Following your lead, I went and had a look at a photo of the carbies on my last GS1000 (an ST) -- which you can see here if you scroll a bit over 1/2 way down -- and what do you know, they appear identical to the carbs I've been quizzing you guys about... :o
So even though they're 33mm across the throat, we technically refer to them as VM30's, yes?
 
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I wonder if they are a relative of the VM34SS carbs off my dead KDX200 project.




While not an exact match they look close.TFB what do the floats look like? The ones off the KDX have the floats on posts attached to the bowl.Was shocked the first time I opened up the bowl.
 
SVSooke, sorry but I can't see many similarities there :confused: ... and no, the float posts aren't attached to the bowl, but to the main body as per most carbs. Yeah I'll bet you were surprised to see that on your carbie, though!
 
I'm thinking the oval bores are similar,other than that not so much.Odd mix of stuff on those carbs all right.Some looks like VM26,the bores look like the VM34's but not much else does.BTW the needle is missing in the second pic,it's in the other carb but opening the slide to get a pic of that was a PITA so I used the needle less carb for that one.Yeah it was a WTF moment opening the carb the first time.
 
All this faffing about just points up to me how little is known about the VM30's. They appear to have been a precursor to the smoothbores in that while a lot of parts are identical to the VM26, there are also some which are shared with the 29 smoothbores - but not the 33 smoothbores...

John Kat warned me a while ago that some parts for them are unobtainable and alternatives have to be used - float needles and seats are one example.

TFB - I don't know what you are intending to do with your set but I know of a Kiwi who is accumulating parts to rebuild the "black pipe" GSX1100 he raced back in the day....he would be very keen to get hold of a set of VM30's.....even ones requiring work.
 
G'day GregT,

My plan is to install them on my GS1000 project, as the current VM28's just can't be tuned properly given the pod filters, the 4-1 exhaust, and the Yoshi cams.

So I will see how they go... and they're still going to need some work yet (new needles and O-rings on the way from Robinsons, and need to fix that busted choke siphon). But if I have no joy tuning them to the GS1000 then I may be interested in exchanging them or part-exchanging them for something else I can try.

Cheers,
Mike.
 
i recently finished off a GS1000 with yosh cams/1075/dyna etc and to get it running while some 33's were coming i rejetted the VM's - on horrible pods too.

Got it pretty good for the open road, still wanted to load up at town speeds. You've got to leave the needles in the middle and get response from enrichening the slow runs (or idle jets which they aren't really...)
i suspect that playing with the idle air correctors would have had it right but the owner loves it on the 33's now so it's academic.
 
tfb said:
G'day GregT,

My plan is to install them on my GS1000 project, as the current VM28's just can't be tuned properly given the pod filters, the 4-1 exhaust, and the Yoshi cams.

So I will see how they go... and they're still going to need some work yet (new needles and O-rings on the way from Robinsons, and need to fix that busted choke siphon). But if I have no joy tuning them to the GS1000 then I may be interested in exchanging them or part-exchanging them for something else I can try.

Cheers,
Mike.
Click to expand...

have you tried ditching the airbox above the battery and clamping a K&N onto the 1st airbox. I did that . looks stock and sure mine has a large dip in the middle of the range but i just ride around it. been too lazy to sort it on 29 smoothies. Did have 33's on it before a mate sold them for drugs. Rode my bike when original owner had it with 33's, stage 1 yosh cams, ported and tingate pipe and powered wheelied in 2nd with out a tug on the bars. All using standard airbox. We all know we hate pods lol
 
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