Last night I finished the installation of my engine and fuel tanks in my Yellow F-18 single. I decided to run the engine up and test everything out today but the fuel system was not primed and had lots of air in the lines. The engine started up Ok but there was quite a few flames from the air in the lines which caused my Tam's Pipe to turn color on the inside. It went from the normal shiny steel look to a almost coper look. I have not noticed anything abnormal such as warping in the pipe but I need some expert advise from some of you guys if this thing is still safe to use.

Brandon

A copper look is fine. But of you get blue-black or purple toss it and get a new one.
Here is what a bad one looks like compared to a new pipe. It got that way after a bad wet start on my old RAM.
It is normal for the pipe to brown a bit after it has been used.

Dave