Glowing Header

[NRPkfx400]

I just put an fmf highflow header on my kfx400 and i started it up and almost instantly it glows red. At this point i had a 130 Main jet in. Then i switched to a 170 Main and there was a lot less backfiring but the pipe still glowed. Is the pipe glowing because it is stainless steel or what?

[cataway]

I'm going to assume its glowing on idle and you changed out the main jet . right ????

[NRPkfx400]

Im not sure if it was in idle i took it around the yard once fullthrottle and came back red.

[z400bs]

Ive got an fmf header and it glows at night or if its cloudy outside. It could be just the heat.