The IVP Continental “detonation” is unburned fuel that lights off in the exhaust. If backfire is through the carb is this fore fire or after fire? 

Mine was from a Slick Magento that was corroded inside.  Slick replaced it.  There were to give me a report of cause which I never received.  No problems since.  Take off the outer cap and inspect.  The corrosion was obvious.

I have an occasional one if I am too lean of peak.  Once I got the GAMIs so there were really balanced and all cylinders peaked in  EGT within .5 gph or less (actually closer to .3 gph now) this went away.

I typically cruise at FL240, 31” MP, 2450 RPM, 70 degrees LOP, CHTs are in the low 300’s, FF about 16 gph.

Carl Cadwell

N25CL IVP 680 hours