Jun 7, 2002
hey, does anyone know anything about the header of WR400F's glowing red hot? i just rebuilt the carb for my bike (98 wr400f) and i started it up tonight and the header started glowing red hot after only 2 min of just running (not riding). my dad and i theorize that the engine may be running too lean. if anyone has any input it is much apreciated.
ps. - i also installed a new throttle cable and it may not be adjusted right as the throttle tends to stick a little. however i don't see this effecting the bike in this way.~thanks


Aug 15, 2000
This is totally normal, and maybe the most commonly asked question about thumpers in general.

In the daylight, outdoors, you just can't see the glow. Fire it up in the garage and...

As for the throttle make sure there is a bit of slack in each cable.

Hope this helps.
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