One of these carbs is not like the others...

See it for yourself (if the image isn't too big):

One carb is definitely different on the bottom and has two uncovered flanges. Any ideas? Solutions?

Picture coming as soon as I get it cropped.

Actually, it sort of looks like the carbs are mixed and matched a bit.

Looks like you have a set of carbs that has the accelerator pump. Normally the carb with the pump is on cylinder #2. What model bike is this?

It's a '79 KZ650SR

It looks like the accelerator pump circuit tubing has been removed from between the carbs. I can clearly see 3 unused ports & a fourth one is kinda visible in the foreground but blurry.

Hmmm, I wonder why the PO would do that? And I wonder what I'm going to do about it. It all seems to be running fine at the moment, but I certainly don't like the idea of something like an accelerator pump missing from the carb.

Anyone have pics of what is supposed to be there? And, should I plug those ports until I can do something about it?

I seem to remember a thread not long ago where one of the more knowledgeable guy's had said, some models have the pump casting on the carb but the pump was not used from the factory. If I remember this right than maybe this is one of those?
Try a search for your carb type on the site. Also go to the Kawasaki parts fiche and see if the carb for your bike lists out all of the accelerator pump parts. This may help.

This set is from a '79 kz650sr. They are for sale...PM me if interested.

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So, if that picture tells me what I should have, then, the PO has somehow disabled/removed the accelerator pump and swapped the number 2 and 3 carburetors around. What purpose could that possibly serve, especially considering it appears that fuel, at the least, has escaped in the form of vapors (read: leaked)?

Motor Head: I doubt it's just an unused casting. I'm sure all that brown in the area is from fuel coming from the flanges and ports.

The whole point is: should I be worried? And do I need to do anything about it?

I'm not familiar with the pumper carbs.
Is your accel pump linkage still there?
You can see in the other posts where the linkage goes, and how the hoses connect to each bowl nipple.
I think there is a check valve inside the bowl also.

sparkn wrote:

...should I be worried? And do I need to do anything about it?

Perhaps the pump has been rendered non-functional, but does twisting the throttle grip cause any fuel to squirt from the nipples?

Good Fortune!