WTF???? i have a 2012 klx 250s. it has been running perfect up till today for some weird reason.. i havent started it in a few weeks and when i did it would not idle, i had the choke out for about a minute or so, then i shut it down when i saw the header turning red hot.. what can cause this ,it was perfectly fine the last time i rode????? any help or suggestions please!!!

 

sounds like an air leak somewhere.
Red pipes are normal though, maybe you just never noticed it before.

 

Having the choke on would make it rich. Exhaust turning red hot can be from a rich condition causing fuel to burn in the pipe, or a timing issue causing the same thing.

Did you turn off the fuel when you let it sit? Fuel could have leaked passed the float causing it to be super rich when you started it.

 

My bike is jetted near perfect with a performance exhaust and at night if I let it idle for very long the header turns red. Nothing to worry about if you have no other issues.

 

Yes I did have the fuel on.. That's most likely it. Any ideas what I should do at this point
Thank you or the help.

 

Chillax

 

IMO...I would not listen to the advice you have been provided thus far. In 35 year of riding & working on motorcycles I have never heard of a a head pipe glowing red hot from a bike runniing too rich. So to me you're running way too lean. I would not Chillax....

 

Yes too lean! fuel cools the combustion.

 

I know mine turns cherry red if I choke for a bit too. Seems pretty common on these bikes and from what I read, it can be reduced by removing the smog junk.

 

Choke was on too long..idle at 4 grand for a couple minutes and you can expect your pipe to glow. If the bike is running fine and you aren't over heating while riding, then it's fine to chillax..lol.