Hi:

           I have been having a tough time with one of my planes that has always given me problems with the engine.  These include being unable to adjust the needle valve  and leaning out in flight etc.  a real nightmare  with many wasted hours attempting to diagnose the problem. 

          The problem was solved when the two piece, Fox, fuel filter came apart while the engine was running. Of course the filter was hidden from sight and I ASSUMED that it was doing its job.  I never had a fuel filter fail in the past! This leaking fuel filter MAY have been the root of my engine problems.  I hope so as what else can fail?  How can it unscrew itself to a point of coming apart?

                                                                                                                                        Stay cool