Fuel leaking through carburetor air filter

Here we go again.  I never figured out an answer to the problem I described above one year ago.    After re-checking float levels and weights (which were correct), I flew for one year, about 50 engine hours without the problem recurring.  Now today, the problem has returned exactly the same as I described above.  Is the seasonal nature a clue?  I don’t know what to do next.  My thinking is back to the return bleed-off orifice, might it be clogged keeping pressure on the needle valves (but then why wouldn’t the needle valves hold anyway).  The air filters on both carbs were dripping wet with fuel and with a small puddle on the floor.  Is this a normal amount of fuel available from a full stroke of the fuel pump assuming it stopped exactly at maximum on the cam?

After drying the filters with paper towels, I ran the engine for 10 minutes.  It ran fine and once again appears to have resolved itself. Do I keep flying while watching for another repeat while the airplane is hangared?

I have no idea if this is a safe situation.  But I sure would like to definitively resolve it.

Any troubleshooting help would be appreciated.

During the last time I turned the engine off (days before coming to the hangar to discover the dripping fuel), I recall shutting down differently than normal.  I turned off the petcock, … and then immediately turned off the ignition, seconds apart, but in that order.  Normally I turn off the engine, …. and then turn off the petcock.  Could the closed petcock (while the engine was still turning) have prevented fuel from being drained from the pressurized side of the fuel pump?  And could that, in turn, have caused the fuel to seep out and into the air filters over the days the plane sat in the hangar?  Would there be enough fuel remaining to drip out of the carbs?   Does anyone know?  This seems feasible to me.

Hi Denis, did you ever find out why this happened?  I have exactly the same issue but from the right side.... Fuel drips from the idle jet air jet orifice.

Paul de Kock wrote:

Hi Denis, did you ever find out why this happened?  I have exactly the same issue but from the right side.... Fuel drips from the idle jet air jet orifice.

See response on other post. Most likely an "O" ring issue.

Paul de Kock wrote:

Hi Denis, did you ever find out why this happened?  I have exactly the same issue but from the right side.... Fuel drips from the idle jet air jet orifice.

Good question.  I am glad mine has resolved, but still not sure what was the cause.  Because mine happened from both carbs at the same time, I came up with a possible theory as to why, which you can read in my previous post to see if this might apply to you (or if what I suggest is even possible). 

In my case, both carbs chose to leak at the same time in the same way, which is why I came up with my own theory when nobody gave any suggestions. My theory is easy enough to test, but I have gone back to my old shutdown order and have forgotten I even had this issue.  I also hate to even test it because when my carbs were leaking, it was very frustrating.

While that was happening I met one other person with an identical problem who also did not know how to fix it.  We were both excited find someone else with the same problem, but this did not lead to resolution.  Misery loves company.  I mentioned I had posted here without any response.  If I see him again, I will ask if his still leaks or if he found a solution, and if so, I will post what I find out.  I'll tell him one more is like us.

To troubleshoot, I would begin with Roger’s suggestion.

Please let us know what happens.