question for weber gurus
 

I just rebuilt my weber 40 IDA 3C carburetors. When the engine stops, I hear gas dripping into the rear carb barrels (cyl 3 and 6). The fuel is actually dripping out (lots of fuel)of the aux venturi fuel outlet, but only on the rear barrels. The only thing that changed during the rebuild is the washer on the needle valve is thicker than the last one. If I am not mistaken this could allow more fuel in to the float bowls making the fuel level too high.

Any ideas?

Check your float levels and make sure the needle valves are closing. Fuel might just trip to the rear barrels because the car is leveled "nose down".

You were right. I checked the needle valves and found that on one carburetor, the valve was only hand tightened. The other carb had the wrong size needle valve. I screwed that up pretty good!. After I tightened the one side, then changed the needle valves on the other, no dripping! Thanks!