4 strokes do get hot.  I'm assuming its the head pipe thats glowing.  Maybe richen the carb up a tad.

The headpipe on my '08 WR450 glows red also.

Is it  normal for a pipe on a 07 yfz 450 to glow red ‎

My YFZ did since it was new. You know after hard riding.

Just ride in front of all your friends at night...

A lot depends on tune.i have a yfz450 with nmotion pipe kit and other mods,had it dyno tuned and I do think I'm more on the lean side for power,but when I ride at night it will glow red.my raptor 700 with duals and a power commander doesn't tho.

no its normal for them to glow red. i have an 06 rmz 450 and with the compression on them they run hot. i would recomend throwing some engine ice in the radiator. keeps it a lot cooler. you dont tend to see the header pipe on a 400 quad or lower cc glow red because they dont have the same power. it is normal but you can try rejetting to reduce it.

Go up a few sizes on the jetting, I had the same issue. come to find out some bikes sold on the west coast were down jetted from the factory. My Bike came with a 130 I believe and it was suppose to have a 140 range. Now its got a 164, I pulled the spark arrester an no more red and the low end pulls harder. Jets are only a few bucks and it only takes 10 mins to change.

Fat fingered from the phone-Corey