I'm in the early stages of rehabbing an NC23 project, and got a better look at the carbs yesterday. They're not too bad, but I discovered that my spare set of carbs don't match—they lack the mounts for the airbox!


(bigger)

Other than this, they seem to be the identical. Can any of you tell what bike the bottom set of carbs came from?

They are nowhere near identical. Bore size, they look like they are for a 400 but off hand I couldn't tell you which one. Any model numbers?

agreed - they look totally different

Edit - actually not that dissimilar after a proper look, maybe they are off a nc29? dont know.

The Haynes manual has pictures of the NC23 and NC29 carbs and they are significantly different, whereas these have identical bowls, and slide covers, linkages… all external appearances match other than the airbox interface. I've yet to take them apart (something else urgent has come up—I was hit by a car on Monday and need to fix that bike) but I suspect the internals are the same.

Nc29 carbs look completly different and have a flat slide...
Looks like you have a set off a nc23rr and a nc23 aero
Stimpy