Hartmut, I believe that a rich fuel mixture causes backfiring in the exhaust. A lean mixture results in a backfire through the carburetor. Lean mixtures usually occur on a cold day and are the usual cause of an engine fire upon starting the engine. Something is causing the mixture to richen when the throttle is closed. Lee
-- "Hartmut Beil" <[EMAIL PROTECTED]> wrote: JohnBackfiring happens when the mixture is too lean. If the exhaust stack has been replaced, the intake elbows might have been taken off as well.I would check for intake leaks at these elbows and for intake leaks in general. If the engine behaves otherwise normal that is. Any abnormality is one indicator more toward the problem. Hartmut ----- Original Message ----- From: John Roach To: [email protected] Sent: Wednesday, October 24, 2007 4:13 AMSubject: [ercoupe-tech] Backfiring on glide I recently replaced the exhaust stack on the pilot's side of the engine. Since that time, the engine seems to be backfiring when I close the throttle to land. I checked it today and the backfiring seems to start between 70 and 65 mph. The A&P has checked everything he can think of and has no idea what is causing the problem. I was flying with the canopy closed and wearing a headset today and even with my poor hearing it seemed disturbingly loud. Any opinions welcome. John Roach N 2427H _____________________________________________________________ Help others. Click here to begin a career in the healthcare industry. http://thirdpartyoffers.juno.com/TGL2111/fc/Ioyw6iighYVI3hSLjuViWYmSvwVhdtHyyC047axTjOe2aKxJpV9oWS/
