kz1000 carbs on a 900?

does anybody know if i can use 1000 carbs on a 900 if i change all the guts and jets? i've got damaged 900 carbs and two sets of spare 1000 carbs.

Do you mean swap VM series KZ1000 carbs for the VM series KZ900 carbs? Sure but don't change the jets and "guts" (whatever that means). If you are using the stock airbox, and the KZ1000 carbs have the stock jetting, they should work fine (if they are VM style carbs and not BS). If you have carbs from a later KZ1000 using BS series carbs, you will have to make a few modifications for them to work. We have a "BS Carburetor Install" link on our website under "wg's Tech Stuff Index" that explains what needs to be done.

by "guts" i meant the slide and needle and floats, etc. yes they are vm series, no i don't have a stock airbox, but the 900 carbs were jetted for the pods and 4-1. i guess i'm trying to verify whether i will even need to change the slide and needle or if they will even fit. what are the main differences between these carbs? (aside from mixture screw location). thanks for any input.

The main difference in slides is that some fit some carbs and don't fit others and the slide cut out. The slide cut out is calibrated to the air jets and the jet needles are calibrated to the needle jets. I would not swap innards unless you really know what you are doing. There were about a dozen VM26 assemblies; all with different BALANCES of components and any jetting changes should be relative to the initial setup from the factory AND the characteristics of that assembly. Some came from the factory lean, some rich and some about right (as Goldilocks would say). The floats will be the same floats in all the 76-80 carbs (the Z1 carbs were different floats and won't work in later carbs) so there isn't any advantage to swapping floats.