VM26SS Carbs

[geol]

The pilot hole on a Suzuki VM26 is of less diameter and thus the pilot mix screws are much sharper (and hence half of them are broken off when an owner seats them). The pilot mix screws on a Kaw seat into a larger diameter hole and are fatter where seated and thus don't break off as easily but will still break off if you over-tighten when seating. The Kaw screws are longer with a knurled head that sticks out from the well they screw into and the Suzuki screws are flat on the top and sit flush or below the surface of the well. A Kaw screw CAN NOT be adjusted so it meters fuel properly. Get Suzuki pilot fuel mixture screws.

mix_screws.jpg

[hannibal]

Wow that's concerning. I bought these pilot screws from Z1 and they list them as fitting both Kawasaki and Suzuki. They look like the Kawa screws in your pic. Now that I think about it, I only used the springs with my original screws since my springs were missing.

[rudeman]

I get my carb parts from SUDCO. They have a huge inventory of parts for Mikuni, Keihin, Hitachi and TK carbs.

[mike1414]

Geol, I have actually gone through a set of those as well and I was unsuccessful with them. I really believe my carbs don't have pilot screws. Nonetheless, that wouldn't explain my leak from the overflow, correct. Also, I don't know if the more recent question was answered, if I alter the size of the needle and seat, would this relate to my overflow at all?

At this point, I'm also looking into just purchasing a new rack of carbs as well, not being able to ride is killing me. I noticed a fellow member has a set of BS32's from an 82 GS750 on here for sale; what carbs uld technically be compatible with my 79 GS750E? Take this set, for example. They are from a Kawasaki, but would they be compatible?

http://www.ebay.com/itm/kz-900-1000-26mm-carbs/172276583341?_trksid=p2352135.c100338.m3726&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20150313114020%26meid%3D0fa79849060048b0a4838d4c0117a651%26pid%3D100338%26rk%3D3%26rkt%3D13%26sd%3D321502981055

[mike1414]

Anyone? Could I fit the slide type 26mm on there? The Kawasaki 900 type 26mm? The needle and seat?

[hannibal]

Not sure what you're asking about the Kawasaki carbs.

I imagine the bigger needle valves are for racing or highly modded applications. If you're motor is draining the bowls faster than the needle valve can refill them, you must be running the motor pretty hard.

[mike1414]

I actually baby it quite a bit, don't throttle down very hard. The 4th bowl overflows, I don't think it necessarily drains dry.

In regards to the Kawi carbs, the older KZ900 seems to run the same (or similar) VM26SS carb - would there be any reason as to why these carbs wouldn't work in my Suzuki? Is the only real difference the location of the throttle stop? From what I've read and what it looks like, there doesn't seem to be any other difference. I would also assume I could just swap my carbs out for simple slide type 26mm Mikunis, yeah?

[geol]

The Kawasaki VM26SC carbs from a KZ900 will work fine but will be far richer initial set up if the jetting is stock. In 77 they leaned the 26s a bit and if you get 78 or 78 1/2 VM26s, they are TOOOOOO lean. Just need to richen up the jetting a bit for the 78s or 78 1/2s. The main different will be the lack of a pilot mixture screw and adjusting the idle circuit air/fuel mix will only with the air screw and it is initially set at 1 3/8 turns out on a 76 VM26. Some folks look at the pilot mix screw on the Suzuki 26s as a benefit as it allows fine tuning but others look at the same screw as a pain in the... well pilot jet. Carb spacing is identical and the only operating difference will be your choke; Kaw VM carbs all have a choke lever/arm and if your current set has a cable to the choke, you will just need to remove the cable.

The float needle seat on VM carbs comes in sizes from 2.0mm to 2.5mm (to my limited knowledge) and obviously the larger allows more flow of fuel. I think that there are other things that limit flow that keep the seat from being the main jet, such as the jet needle/seat, main jet and fuel rail size. Most of the seats in kits are 2.0 as that is the most common application for factory VM carbs of any sort. If you bike were operated up higher in the rpm range a lot of the time and you had engine mods, perhaps larger seats would benefit (along with larger fuel pipes) but a stock bike, well, not much difference.

[mike1414]

Exactly the explanation I was hoping for, Geol. Thank you for that. So, that being said, basically changing the needle and seat won't matter. I can't figure out for the life of me these carbs, so I may just purchase more and just tinker with these over time.

So an appropriate substitution could be the Kawi 26mm; could I plug in the slide-type VM26's and have those work? Why does my model have the VM26 "SS" as compared to the slide-type?

[geol]

They are all VM26SS; ALL Suzuki 26s and ALL Kaw 26s except the 76/77 KZ900A and KZ900B and they were VM26SC. I HAVE NO IDEA WHY. They will all fit but you need to jet them according to your setup. In other words, the 76/77 VM26 from a KZ900; they are very rich from factory. Little rejet is needed for pods/pipe, etc. The 77 carbs from any KZ (900 or 1000) work but a main jet bump is needed for pods/pipe and the 78 and 78 1/2 need a bump in main jet and #20 pilot jets. The reason, just like Suzuki, is that the air jet size and slide cutaway change from year to year for reasons that are not intuitively obvious to an ignorant Texan. All can work fine if jetted correctly.

And your float needle seat? 2.0 or 2.3 makes almost no difference in a stock bike of any sort.

[hannibal]

Take a look at this: http://members.dslextreme.com/users/...eight.html#A01

[mike1414]

Hannibal, thank you for posting that. I could not remember the site nor the member's name that runs the site, so now I can bookmark that for all my future needs. And, Geol, you have been TREMENDOUSLY helpful with all of your explanations and imparting your knowledge. You deserve to have yourself a nice cold beer and relish in your ability to translate your wisdom into helpful tips and explanations. I'm gonna look around the forum and web for some carbs, and in the meantime tinker with mine and see if I can't get this thing on the road again.

[mike1414]

Just an update in case anyone has been following - I ordered a pair of Kawi VM carbs and first off, no leaks! That's a huge plus, of course. I got the rack for about $115. They came with a 122.5 main and 17.5 pilot jet. I switched them out to my old 117.5 and 15's, but it ran too lean. I now plugged back in the 122.5/17.5 combo, and it seems like it's a bit too rich with slight white smoke from the exhaust and bogging in the first 1/4 throttle, but I think I may plug the 15 pilots back in and play around a bit and see what I can make work. The Kawi carbs came without the spring on the throttle stop, but I installed one, still idles at 2200 though. So, I figure a little tinkering with the jetting and the throttle return and I should be good to go! Thanks to all that have helped over the last few months.

[hannibal]

Glad to hear! Where'd you find the carbs?

Do the Kawi carbs have an idle adjustment screw like the "regular" Suzuki VM carbs?

[mike1414]

Got a set off of eBay. I had a couple in mind, but this set looked best. The Kawasaki idle adjustment screw is just on the top of the carbs as compared to the Suzuki on the bottom. So after messing with it, the bike ran, but still rich. So once I adjust my pilot jet, it should fix the hanging RPMs and throttle bogging I'd assume. Hoping for some luck here finally!