Help! Carb 2 STILL leaking

I've taken the carbs out of my '81 KZ750 and cleaned them up. Found a cracked overflow tube on carb 1, JB weld fixes it. Put them back in, gas leaking from the bowl on carb 2. Replaced float bowl gaskets this afternoon, put carbs back in, STILL leaking from the same place. Seems to be coming from on of the screws on the bowl, but with the bike leaning on the stand, this may just be the lowest point of the carb. Any ideas???

Gravity is a plague upon your house.... every carburetor bike on earth is subject to this effect. The needle valves in the carbs (which are driven up by the floats) are not sealing off the fuel flow.

1) We all who ride old bikes make sure to turn the petcock OFF when we park them for any length of time. If your petcock is not sealing tightly, the carbs will probably seep gas. You may need to rebuild it if it won't seal tight.

2) If the fuel level in that carb is set too high, it will leak gas because it doesn't cut off the flow.

3) HERE IS THE MAIN CAUSE: the tapered end of the needle doesn't seal tightly into the brass seat. Put the needle in a low speed drill and use #600 paper to polish that tapered section dead smooth. Use a Q-tip and brass polish to make the inside of the brass seat very smooth and shiny. I do this on mine about every six months to keep them from seeping gas past the needles.

Here's a link to an earlier KZR thread with some good information on this topic.

Click Here

Good Luck!