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What carbs are these?

  • Thread starter Thread starter Easy Rider
  • Start date Start date
E

Easy Rider

Guest
I want to thank all the contributors that make GS Resources such a great archieve of information. The site has really helped me get my 1979 Suzuki GS1000E on the out of the garage and on the road.

I have a general question about my carbs. I just finished putting in dynojet stage 3 main and needle jets in. However, when I went to adjust my pilot fuel screw there were none to be found. Upon some research it appears vm29's don't have pilot fuel screws. I'm wondering if my carbs are vm29's. It's also possible that they're vm26's and I'm missing something. I've included pictures. Thanks for the help.
 
I pic of the whole unit would be nice, but those dont look like 26 slides...Might be 28 pumpers or 29s...Give us a better pic?
 
More Pictures

More Pictures

Underside pictures, isn't there suppose to be a pilot fuel screw in that hole?
 
Nope. Those caps allow you to pull the main jets without removing the carbs from the bike, or atleast without upsetting much. Im guessing these are definately pumpers or smoothies, they ARE NOT standard VM26SS carbs. I dont see an accelerator pump in the other pics, Im going with smoothbores...
 
More Pictures

More Pictures

Back shot. Sorry about the tape. I can take it off and reshoot if it helps.
 
Particular shots

Particular shots

If anyone would like to see a particular shot, just ask.

I guess my next question would be if these are smoothbores, like vm29's. Are these going to run properly with the DJ stage three kit? Here's what I put in them.

Main Jet: 138
Needle Jet: DJ Needle at 3 1/2 notches

Pilot Air Screw: Haven't touched it

Thanks for the input.
 
More information

More information

I guess I should also mention I'm running a 4-in-1 pipe (type I'm unsure) and true K&N pod filters.

Having the forum members support on this is great. Thanks again.
 
With the manifold I would guess they are from a Kawasaki rather than a Suzuki but I have no idea what model.
 
Those are VM29 smoothbores. I have the same ones on my bike. Apparently, these are highly sought after. I can tell you that they produce nice crisp throttle response. I have always had a slight miss on higher revs, and have finally nailed the problem down to a loose connector on a wire to the #'s 2&3 coil. I fixed this and am just waiting for my points to come in. Then I am going to finally be able to go through the rev range without any glitches, hopefully. I should get a real good feel for how these carbs perform!!!!!!:D
 
Easy Rider said:
If anyone would like to see a particular shot, just ask.

I guess my next question would be if these are smoothbores, like vm29's. Are these going to run properly with the DJ stage three kit? Here's what I put in them.

Main Jet: 138
Needle Jet: DJ Needle at 3 1/2 notches

Pilot Air Screw: Haven't touched it

Thanks for the input.
Click to expand...

Those are VM29's, and I couldn't tell you about the DJ jets, as they are completely different than Mukuni's. My pilot size is 25, main 120, and the clip is in the middle position.
 
I think the DJ138 jets are much too large. There is a tremendous loss of power at 3/4 to full thottle and the plugs are dark. I'm going to install a set of Mikuni VM120 jets and see if that helps.

Also I'm not sure what pilot jets I'm running (25?) but I'd like to install 20 because my pilot air screw is out quite a few turns.

I think the DJ needle is close at 3.5.

Thanks cafekid, mad, and slip for the help on figuring out what carbs I'm dealing with.

I'll keep this updated with my tuning journey. Finding what tune works with VM29s on a GS1000 with a pipe and pods.
 
those are 29MM smoothies start with 25 pilots needle at position 3 and 120 mains that should put you pretty close
i have a set on mine as well
what pipe do you have ?
according to the mikuni to DJ converter that i got form here you should use the DJ 128 mainjet that equals a mikuni jet of 120
from what i can tell at this point with the DJ 138 your 4 sizes too big on the mains for your bike
 
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What kind of Dynojet kit did you get? Do they make one for the VM29?

My 1000S came with VM29's when I bought the bike. Since I don't care about eeking out every last HP I sold them on ebay, picked up a stock set of carbs, and put about $600 profit in my pocket to help fund the rest of the restoration.:)
 
29 and 33 smoothbores appear identical who measured the inner venturi diameter?

better start at 127.5 mains and the needle in the middle which may still be too much fuel.

depending on your engine pilot jet choice is going to be biggest tuning factor.

12.5 or 15 or 17.5 pilot sizes. maybe a 20 if you have massive low lift flow from a port job and bigger intake valves

no dyno jet kit !!!! these are very easy to tune -- for half throttle and higher. street use is going to require patience.
 
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trippivot said:
29 and 33 smoothbores appear identical who measured the inner venturi diameter?

better start at 127.5 mains and the needle in the middle which may still be too much fuel.

depending on your engine pilot jet choice is going to be biggest tuning factor.

12.5 or 15 or 17.5 pilot sizes. maybe a 20 if you have massive low lift flow from a port job and bigger intake valves

no dyno jet kit !!!! these are very easy to tune -- for half throttle and higher. street use is going to require patience.
Click to expand...
Agreed, VMs are cake to tune, I wish they were all so easy! And yes, they will require a bit of patience and a learned throttle hand...
 
trippivot said:
29 and 33 smoothbores appear identical who measured the inner venturi diameter?
Click to expand...
I don't think so. Stock vm26mm carbs and 29mm smoothbores resemble each other, but 33mm smoothbores look totally different. 33's have gradual tapered inlet throats, 2 screw flat tops (versus 3 screw cupped tops for 29's), totally different racks that they mount to. Dar
 
Well I just installed the 120 main jets and let me tell you what a difference that made. Needless to say the clutch is not able to hold all the power at the high rpms.

On the downside it appears the Dynojet needles at 3 1/2 are not going to work. I haven't pulled the plugs yet but it seemed to be rich in the mid throttle. I'm planning on re-installing the stock needles at position 3 and see how that works.

Also I confirmed my pilot jets are #25. My first impression is it's slightly rich but I have yet to confirm with a plug read.

Thanks for everyones feedback. This thread has been a real life saver.
 
Easy Rider said:
Well I just installed the 120 main jets and let me tell you what a difference that made. Needless to say the clutch is not able to hold all the power at the high rpms.

On the downside it appears the Dynojet needles at 3 1/2 are not going to work. I haven't pulled the plugs yet but it seemed to be rich in the mid throttle. I'm planning on re-installing the stock needles at position 3 and see how that works.

Also I confirmed my pilot jets are #25. My first impression is it's slightly rich but I have yet to confirm with a plug read.

Thanks for everyone's feedback. This thread has been a real life saver.
Click to expand...
yes put the stock needles back in and set them to P3 and see how that goes if you have a really free flowing pipe then you might need to go to P4 as i did but try P3 first
if you feel that the pilots are too rich with 25's in then go down to 22.5's check it out and see you should do some plug chops and aee what they tell you
remember that rich or lean will not be determined by RPM or speed
but by the throttle position and the throttle position will tell you what circuit to adjust
idle to 1/4= pilot jet and air screws
1/4 to 3/4 = needle jet & jet needle
3/4 to WOT = main jet
 
Easy Rider said:
Well I just installed the 120 main jets and let me tell you what a difference that made. Needless to say the clutch is not able to hold all the power at the high rpms.

On the downside it appears the Dynojet needles at 3 1/2 are not going to work. I haven't pulled the plugs yet but it seemed to be rich in the mid throttle. I'm planning on re-installing the stock needles at position 3 and see how that works.

Also I confirmed my pilot jets are #25. My first impression is it's slightly rich but I have yet to confirm with a plug read.

Thanks for everyones feedback. This thread has been a real life saver.
Click to expand...

I have the same carbs with a Kerker pipe and K&N pods. A 122.5 main and a 22.5 pilot have mine dialed in pretty well.
 
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