I run the stock pipe so far with no problems. You may have to tinker with the acceleration parameters as on hot days mine would not go above 50% power. I originally had an old Jetcat 120 in it and it was even worse. On skymadter's website they do show customer pics of the plane with 140's in them do it tells me they are endorsing that power. On a side note I brlieve you are the man I sold a gray ziroli zero to about 10 years back