Why would this happen on a fuel injected machine? The exhause right behind the heat guard is glowing bright red.

 

Its pretty common for the header to glow red when they are stock since they come lean from the factory but not really heard anyones glowing that far back.

It being FI really has no effect on it since it doesnt have a O2 sensor on it, thats why you need a FI controller to add mods.

If you have added mods or removed your baffle or lid without adding a controller this could be why its glowing so bad.

 

It's normal for them to glow. The 450's do it too. After market exhaust seem to glow even more. I suppose because they are thinner.

 

I havn't added anything to it...not even removing the air box lid. I just don't know why it is glowing red and even from behind the heat guard it feels crazy hot even through riding pants on my leg. It doesn't seem normal. My 660 never had this issue... but i guess if it isn't hurting anything?

 

Na, its fine. I know its a big complaint on the yfz450. Apparently the design of Yamaha moves the pipe out farther than other make's causing it to heat up your leg. I don't even think I have any hair left on the inside of my right leg.

 

Its probally fine but it doesnt hurt to do some plug checks and make sure your not to lean.

 

Exactly!! Check that its not running lean!! My Raptor is bone stock and has never glowed red!!!