Fired my '09 KLX 250 up for the first time this winter (hasn't been run in a couple of months), ran her for a few minutes with choke on and noticed the exhaust pipe near the header was glowing red hot. The motor didn't seem too hot and appeared to be running fine. I shut it down for fear something was wrong. I live in Buffalo, New York so winter riding is pretty much out. I figured I would fire it up and maybe take it on some short jaunts on warmer days this winter instead of winterizing it. I keep it in my garage, so the temperature doesn't get too cold, probably rarely gets below freezing. Does anyone know why the pipe is so hot?

 

Nah, its normal.

They run a bit lean stock, and a lean condition will increase the temperature, so you could consider a re-jet.
But with the choke on it shouldn't be running lean.

Either way it's nothing to worry about IMO.

 

I had that exact same thing happen to me a few weeks ago. I fired up the bike and had the choke on when my cell rang. I stepped away and took the call. I came back after maybe 3 minutes (I'm not sure) and the header was a nice bright orange. Yikes! I pushed in the choke and the color went away. Apparently no harm done, but I won't be doing that again.

 

built in ciggarett lighter?

 

mines an 06 and jetted and that sucker glows bright bright red if I hold it 3,000 rpm when I have the gas shut off. The closer it get to running out of gas the brighter it gets. I let it idle now until it stalls. I figured as bright as it was glowing, it would warp bent buckle or start leaking at the head. At idle it still glows but not like when I rev it

 

The glowing with choke on comes from the air fuel mixture that is being pulled into the head pipe. The rich condition from added fuel just brings the flame front into head pipe causing glowing.The mx pipes and atv pipes that use titanium head pipes will glow.I have seen customers bring there stuff back to shops after riding at night thinking there is something wrong. I think that thin walled pipes will show up very quickly glowing from rich or lean conditions.That is why alot of aftermarket v-twin exhausts have clamp on chrome to keep from blueing.

 

Cool. Thanks for all the replies.

 

Another red hot header here. It would only run for a second then shut off , did that about a dozen times. Then a shot of starting fluid and she was running. Alot of popping and would not idle even when it warmed up. Sometimes even when it's warmer I have to ride it a few miles before it will idle without revving. I guess the cold air is more dense and messes with the jetting, not to mention 2 month old gas in the tank.

 

mine did until I re-jetted it.

 

had a similar issue with backfires on an XR500. Lack of airflow.