glowing red

[red_atv]

a friend of mine has a 06 yfz. he fired it up and rode about 15 minutes. the head pipe was glowing red. it was at night but i dont think its supposed to be that hot. hes got a jet kit in the carb and a slip-on on it. other than that its stock. any help would be appreciated. it starts right up and sounds pretty good but i can light a cigar off the pipe.

[jdlove...yfz450]

yes it is normal. unfortunitly they run extremly hot. i have an 06 and we noticed the same thing. after i changed my header to gytr it stopped. i think the stainless steel stock header is pretty thin. i know you mentioned he has it jetted, if it is running too lean it will be alot worse. good luck

[florentino]

it will run cooler .

[red_atv]

got a new pro circuit one. works great. thanks.

[#17YFZRACER]

does it backfire? if it does it could be to lean. a motor can backfire from being 2 rich or also 2 lean. i dont know how much you know about jetting but all a backfire is is fuel in the head pipe that gets burned making a small explosion and a popping sound (backfire). that happens when the motor is to rich or lean. a lean motor will run hotter than a motor that is tuned right. if the mixture in the head is 2 lean the fuel molecules are spaced 2 far apart in the head for the spark to burn all of it then u get a backfire and a hot motor. when it is rich the mixture just has 2 much fuel for the spark 2 burn. the head pipe will be a little red-ish orange color but that is fine. but it shouldnt be more than a couple inches up the pipe. just play with the jetting a little and good luck.