New guy here, looking for help.

Hey guys, I have been a BMW tech for while now and work on VW's for fun but I have never really had a reason to mess with carburetors before, so they are new to me. I have recently accuired a 78 kz650 SR that was my fathers. It has been sitting in a storage bin under a tarp for somewhere around 5-6 years.
I took the carbs off and cleaned/freed the floats and needles but 2 of them still over flow. (the 2 that were the cleanest?) So my question is, if the floats/needles are free, then where else do I look to solve the over flow situation?

You should be able to clean the float needle and orifice with a Q-tip and carb cleaner (do not use anything abrasive!) so they mate together and don't leak. If you can't get them to stop leaking they may be damaged, so you may want to replace them. Also, if you mixed the parts up between the carbs (a no-no), you may not have a matched pair. If this is the case, try switching the float needles between the 2 carbs that leak to see if that helps. If you need to replace them the good news is that they are still available from Kawasaki, so any dealer can get them. Assuming you have the original carbs; they are part number 16030-1001 "Float Valave Assembly." They come as a matched set of needle and orifice, so don't mix them up. Ronayers.com lists them at $25.43 per set. Ed

Another possibility is that you installed the floats upside down, or accidentally bent the float tangs so the float valves never close. Ed

Hello, VdubbPeach, and WELCOME to KZr!

Some of the possible causes for gasoline discharge from overflow would include:
Imperfect fit of float needle into seat orifice;
Crud or grit at float needle interface with seat orifice;
Worn pointed tip of float needle;
Failure during re-assembly to keep same float needle with its same seat;
Incorrect float height adjustment (tang setting);
Float bent or rubbing against bowl;
Float installed upside down;
Float leaking;
Cracked overflow tube (often repairable).

Good Fortune!

Thank you for the warm welcome! I was glad to see a specific fourm for these bikes and all the activity of the fourm.

I was very careful not to flip parts or switch parts between carbs. Sounds like my problem is either the needle being worn or something such as grit is stoping it from closing off. looks like they are coming back apart today! thanks for the help guys.

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For seemingly inexplicable reasons, a freshly re-assembled carb may initially discharge through the overflow circuit, even when supplied with fresh gasoline passing through a good aftermarket inline fuel filter.

With engine at idle rpm, and fuel discharging from an overflow nipple/hose, the discharge may often be eliminated by rapping smartly and repeatedly against the side of the float bowl with a plastic mallet or large screw driver handle. Usually takes less than a dozen raps.

Am not quite sure why this works, but has often worked for me, and should be worth a try. And would do this before again disassembling the carbs for further cleaning efforts.

If the overflow tube is cracked or loose at its connection inside the bowl, any crack may be very fine and difficult to notice. Such tube leakage may be readily tested with float bowl removed from the carb and filled to the brim of the overflow tube.

Good Fortune!