My Piper Archer (O-360 Carb) has been having a hesitation problem at around 1200 to 1500 RPM when advancing the throttle so I suspect an induction leak. I also notice no slight RPM rise when changing the mixture to idle cut-off and the Idle Mixture adjustment does not produce an RPM rise. The engine runs fine otherwise with good static RPMs. I did an in-flight induction leak test and found that the number 1 and 2 cylinder EGTs had very little temperature drop when comparing WOT and 2000 RPM power settings. The number 3 and 4 cylinder EGTs both had a drop of about 150F temperature drop when comparing WOT and 2000 RPM power settings. I believe this indicates there is a leak on the number 1 and 2 cylinder intake paths. What is the simplest way to to ground test and find the leak(s) or rule out leaks? I am reading that air pressure from a clean vacuum cleaner on the carb heat port is a good way to pressurize the intake and then spray on soapy water to look for bubbles/leaks. Is there a common leak area associated with number 1 and 2 cylinders or possibly both intake tubes are leaking?