Cannot figure out this leak

Hi guys,
I need some suggestions. Maybe someone else has experienced this. I cannot stop or find the source of a very slow leak in my #3 and #4 float bowls.
It's a very slow leak from the overflow tube. #4 doesn't really drip , but is wet when I touch it. #3 will drip maybe once every 2 minutes when petcock is on.
I've checked everything I can think of. My fuel levels are lower than 4mm from the top of the bowl. It seems I'm running lean because of this.
I've checked the floats to see if they were taking in any gas.
I've removed and filled the floatbowl to see if the overflow pipe was cracked.
It is not the drain screw.
I've removed the floatbowl and turned on the petcock. I can easily stop the gas flow by closing the float needle by hand.

The only think I can think of that I just thought of could be if these float valves are actually shorter than they are supposed to be. I got them from Z1.

Any thought?

If the tang on the float is on too much of a angle, the needle will cock sideways and leak. They should be almost level. Bend the arms then bend the tang to fine adjust the float.
Steve

You may want to try GENTLY cleaning the float valve needle and orifice with a Q-tip. Don't use anything abrasive, maybe some carb cleaner or such. If there is any residue on the needle or in the orifice the needle may not seat well under normal float pressure. Ed

I agree with Ed about cleaning the float seats. I differ from his advice though in that I recommend using a small piece of gray scotchbrite pad, hopefully a chunk that's worn out some already. You don't want a lot of grit, just a little to assure there is no foreign material stuck inside.