Carb opinion

I bought a "79 KZ1000 LTD from a fellow in mid October (not running carbs were off of it). He said it wasn't running properly but he never opened up the carbs, when I took the carbs apart they had lots of rust in them, so I cleaned them up put them on the bike & it fired right up, runs & idles well on the side stand but there is a foot of snow on the ground so I won't be test driving it for awhile. He also gave me a work order from the season before from a shop that put pods on, jetted, & dynoed it, along with a rack of Z12 carbs less the bowls. The story is that the Z12 carbs that were on it (research tells me they were not stock on a '79) had one slide stuck so they didn't use them, they used a set of VM26's from a GS750 & the bowls from the Z12"s. I spoke to the shop that did the work & they said the bike was running good after they tuned it. 
I have since fixed the problem with the slide on the Z12 carb but they will still need to be cleaned & jetted if I were to use them. One thing I'm not fond of with the GS carbs is they have both air & fuel adjustment screws. (more tuning headaches ?)
Research tells me the Z12"s are not the stock carbs to that bike, were used on the 900"s, but I read somewhere that they are supposed to be very good carbs & are commonly used on KZ1000"s.
So I guess my question is, should I rebuild the Z12's & put them on, or just go with the GS carbs if they run OK ?
 

Since the GS carbs were dyno tuned, and supposedly run well, I'd run them.  Assuming you got the rust out, they should be fine.  The GS version VM's are very similar to the KZ version, so it's not like they are inferior carbs or anything.  Regarding the other set, I'd rebuild those too.  Why not?  Save them for a rainy day.  Oh, and figure out where that rust came from and fix it.  I'm guessing your gas tank.  

The gas tank has been cleaned & coated (kind of bluish color) I don't think it's had gas in it since, so the previous owner must have known the problem. Lots of holes in his story when I bought it. I think he must have played around with the air & fuel screws, they ranged from 1/4 turn out to 2 1/2  so I will probably have to adjust them when I hit the street, for now I set them all at 1 1/2 turns. I think I will rebuild the Z12 carbs & look for some float bowls for them. 

Typically, the pilot fuel screw should be set at about 7/8 of one turn, and the air screw 1.5.  Those are reasonable starting points anyway.

OK thanks, I wasn't sure where to start with on the adjustment screws. 

I'm not sure what you mean by "Z12" carbs.  Do you mean Z1?  There were different versions of them.  Could you provide a photo?

 

wrote:

I'm not sure what you mean by "Z12" carbs.  Do you mean Z1?  There were different versions of them.  Could you provide a photo?


 

My guess would be Z1R 

I think he's referring to the code stamped into the flange of the carb.  Z12 00 to be more specific.  These are late 900 carbs.  They have pilot air screws, a joining plate across the top, and some slightly different bits as compared to the later VM26's.  

The 79 LTD used VM26SS carbs.  The cutaway was 2 mm, while the cutaway on the KZ900 carbs was 1.5 mm.  Check your cutaway to see which ones you have.  If they are from a KZ900 they are in my opinion the best version of all of the VM26SS carbs used in KZ900/1000 bikes from that era.  I have them on my 1980 LTD 1000.  Once again...photos would be quite helpful.

They are as Nessism has described,

Yes the Z12 over 00 is the # on the flange.
What is the carb cutaway ?
I just took a pic of the one carb I separated from the rack, there is a plate that attaches to the top of all the carbs
There is no accelerator pump on these or the GS carbs

The cutaway is that missing section on the bottom of the slide.  There should be a number on the slide...I think on the bottom.  It will either be 1.5 or 2.0.  

I can see the air/fuel adjuster on the intake side of the carb.  This is evidence of them being from a KZ900.

I noticed a date code on one of the photos.  65.  That means either June/75 or May/76.  In either case it points to those being from a KZ900.  The cutaway will be definitive.