KZ900 Carbs - have you seen a set like this before

I soaked these carbs in Pine Sol (it works!) and started taking them apart to clean the passageways.

The cylindrical part where you might expect the fuel adjustment screw appears to be sealed off.

Does this look unusual? I recall if I have seen carbs like this before.

KZ900 Mikuni 26mm manual slide carbs are supposed to have side-located air screws to adjust the pilot circuits.



As contrasted with similar carbs having bottom located mixture screws for adjusting the pilot circuits.

The pilot adjustment screws on some carbs might have a plug to discourage EPA-hating reprobates from overly enrichening the pilot circuits. Where fitted, such plugs are readily removable by a very shallow drilled metal screw inserted and pulled out with a pair of pliers. But watch out for the circling black helicopters.

Good Fortune!

Hi Patton,

Yes the carbs have the air screws on the side. I don't remember seeing the bottom parts blocked off before - maybe I have seen it before and just forgot.

Thanks for the info and I will continue with the cleaning.

Mike

The stock KZ900-B1 LTD Mikumi 26mm manual slide carbs, viewed from the bottom, have the protruding part circled in the following picture. But with the protruding part being more "surrounded" than shown in the picture:







I looked high and low for a bottom view of the KZ900 carbs that clearly show the particular area involved, and have tentatively concluded that your posted picture is the only such picture on the planet. :lol:

Hopefully others will have better information about the differences, and which might be more typical.

Good Fortune!

Those are 100% identical to the carbs from my 1976 KZ900 A4. It's impossible to get a perfectly clear picture of the bottom while they are still on the bike but you can see that they are plugged off. The pilot adjustment is on the side.

Oh yeah, mine even have that same steel plate that goes across the tops of the carbs.

Thanks for the additional info. BTW mine is an "A" model too.

The bike is for the most part stock but that's no guarantee that these carbs were on it when it left the factory.

I just bought a set of vm26 carbs off a gs750. They have both pilot air screw on the side and enriching screw on the bottom. They are going on a kz650. Do you guys have any idea how I should start tuning these carbs?

thanks,
Nick

I guess it is dependent upon just which set of carbs you have. The early sets used on the 77 GS750s have a large cutaway (2.5) on the slide and had rather large pilot jets (22.5), the next version has an even larger pilot jet (27.5) and a cutaway of 1.5 - both of these tend to be harder to tune than the later ones which had smaller pilot jets (15) and a smaller cutaway.

As to the settings for carbs with both a pilot and air screw I would suggest one of 2 ways to do it.

Either screw the pilot screw all the way in and in essence block it off, and then use just the air screw for adjustment. This was actually recommended by Kawasaki,via microfiche for the kz650 B models that had both types of adjustments on the smaller vm24 carbs.

The other would be to set the pilot screw (bottom of carb) at 1 3/4 out from lightly seated, and the air screw (side of carb) at 1 3/8 from lightly seated. I would then only use the air screw for any additional tuning needed.

my cutaways are 1.5. so does this mean i should shoot for bigger than a 22.5 pilot?

If the pilot enrichment screw is seated all the way in, won't this stop all pilot circuit flow?

thanks,Nick

Patton wrote: The stock KZ900-B1 LTD Mikumi 26mm manual slide carbs, viewed from the bottom, have the protruding part circled in the following picture. But with the protruding part being more "surrounded" than shown in the picture:

I looked high and low for a bottom view of the KZ900 carbs that clearly show the particular area involved, and have tentatively concluded that your posted picture is the only such picture on the planet. :lol:

Hopefully others will have better information about the differences, and which might be more typical.

Good Fortune!

A better pic --



Good Fortune!

NicMac we are sort of taking this post in another direction. Maybe you should start a new one with your questions about your carbs off of a GS750 that have both an air screw and a pilot screw. I will be happy to respond to it with my 2cents.