26mm Mukini carb.

[deward66]

I am trying to find out about a spigot mount 26mm. The 26mm for the Road Toad is a bottom float bowl drain carb., this one has a side float bowl drain with the main jet in it.This is like the 28-34 carbs.
I cannot find anything about this carb. I have one, so at one point they were made just don't know what to do about jetting this one.
Any body got any ideas?

[Hydraulic Jack]

Not sure what your question is exactly, but if you want to know if there is a difference in how to go about jetting the different style carb, the process is the same no matter whose carb you have, and I would expect the jets to be the same between the two styles assuming both are Mikuni. But just in case, there are websites that offer different jets for a variety of carbs. Take a look at Jets-R-Us. They include photos of their jets so you can compare physical features.

Bottom line: "what to do about jetting this one.." Follow the same procedure for jetting any carburetor, start rich and work your way back. I have never experienced a significant difference in jetting as between the two styles of carbs, and whether the main jet is mounted under the needle jet or in the bowl, the distance from jet to Venturi is not significantly different and makes little to no difference in which jet the engine will need.

[efkruger]

"Jets-R-Us" I learned my new thing for the day. Thanks Jack

[matt glascock]

That side float bowl drain is a banjo bolt that holds the main jet. It allows changing the main jet quickly and can also be removed for draining the float bowl. I think it was mainly used on racing and enduro models like the Super Rat and Wombat where rejetting on the fly is a nifty option.

[Makotosun]

Do some research, as the side mount (banjo bolt) carbs I believe take a slightly larger jet than the bottom mount version, in part due to the lengthier fuel path. The carbs, which are otherwise the same, flow a bit different.

Depending on the particular carb, you can usually interchange the bowl, converting one type to the other. This at least appears true with the Mikuni carbs.

[matt glascock]

I'm not sure how that would work. What would you do with the main jet mounted to the top of the carburetor?

[taber hodaka]

Matt I am not sure what you are asking?------------Clarence

[Makotosun]

The side type carb (flange mount) has the main jet on the banjo bolt (#8), there is usually a critical “O” ring on the extension that is at the bottom of the needle jet. (Item #7)

The bottom drain (spigot mount) has the main (#6) mounted on the bottom of the needle jet.

Given those photos, what is your question?

Note: the photos are Yamaha carbs, but the VM series Mikunis we’re pretty universal.

[matt glascock]

Sorry if I was unclear Clarence. Gary, my question pertains to your first post on this thread. I can't see how the float bowls are interchangeable since one has the main jet held by the banjo bolt in the bowl and the other one does not.

[Makotosun]

The little extension that sticks down into the bottom of the bowl, with the o ring unscrews, and the main jet replaces it. You just relocate the jet.

On the side mounts (or banjo bolt mount) the fuel is meters through the main, then picked up bu the piece with the o ring. That is why if the o ring is missing, the carb won’t operate correctly.

One other tidbit, the wombats (not the combats) use an almost identical Mikuni to the early Yamaha 125/175 Enduros. So if you are needing rebuild parts, they will interchange. One of the rebuild kits I had lists both bikes on the instructions!

[matt glascock]

Excellent. Now this all makes perfect sense. Thanks for straightening that up for me Gary.