I was referring to the eariler post, which stated red was 2200 F.
Anyway, do you have any other symptoms of lean running? Popping exhaust, hard starting cold, surging steady state throttle? Do you have any type of advanced timing, other than stock. Advanced timing will also cause high temps.

 

Go to a night motocross race and look at the bikes on the starting line. Every single 4-stroke will have cherry red header pipes, doesn't matter if it's a guy on a box-stock one or a fully modified one. When I got my 1st "modern" thumper for mx, I was on the starting line and the guy next to me told me he'd let me go first.....when I asked why he pointed at my header and said he didn't want that on top of him if we got tangled up [img]i/expressions/face-icon-small-smile.gif[/img]

I do plug checks and listen for popping on deceleration, if I'm good on the plug and not getting any popping I don't worry about it.

 

I've heard all these answers for the glowing pipe, and yep the yfz is famous for it. But if you header is glowing "any color" or if the chrome is dark bluing more than a couple of inches from the exhause port, following Hightowers advice would be worth while.

Once we got our 3 yfzs on an air fuel gauge and jetted right, the glowing stopped.

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Hightower, seems im not the only one lol

The glowing def does not seem normal to me, my stock bike did it after a long hot day of ridin hard for hours, but then and only then, now playin wit the carb it does it even if its 10* outside and i just ride for 30 seconds, gotta play some more wit the carb, cant be right

 

That is actually how I verify my jetting and needle adjustments. Ride at night and if it barely shows red on the pipe its still lean at some point. If your WOT then obviously its your main jet size. If just normal throttle then its your needle position. Look at it this way, us telling you its lean is good news for you and more power. If your running that lean...it WANTS more fuel = more power. But make sure you determine at what throttle position it makes the pipe glow, then go fatter where needed.

Also, a stock quad with a glowing head pipe can easily be explained. The factory setting isnt right for your elevation. Also the weight of the rider is more stress on the engine.....this shows in the sand more.

 

simply ceramic coating a header to disipate heat faster directly contributes to hp, as the lower headpipe temp equals lower head temp equals lower coolant and oil temp equals lower temp everywhere and this is no secret. when some people go to these lengths for the subtle gains available, it only seems all too logical to at least correct jetting for proper combustion temp.
better performance and longer long term engine life will certainly be obtained with a properly tuned machine that does not have headers that glow, not to mention longer cosmetic appeal from not getting blasted with roost and steeming water during a glow.
so I got the temps wrong blabbing off the top of my head, but regardless aluminum flows like water at the temp of glowing steel and I sure won't ignore a glowing pipe when its as simple as changing a $3 jet to get rid of it and increase the life of the motor in the process.

when I ran a stock carb I went from the stock 40 pilot to a 45, don't know what they come with stock these days but if they are still sending them out the door lean like they used then this is a place for you guys to start. seems like I ran my idle mix screw 3-1/2 turns out too, but don't remember exactly. Hope this helps.

 

If you guys are concerned about the glowing headers and you think your jetting is on use a temp gun on the headers to c what temp they era. You can buy a temp gun at sears or most hobby shops. I think the one I bought at sears ran me 50 or 60 bucks. They are infra red and very accurate. I have mine from when I was racing r/c nitro buggies. They make a good addition to any tool box.

 

Just a thought but if the header is Titanium or stainless they will turn red much faster then the stock header and at a much lower temperature.


I'm just sayin.....

 

>>stainless melts at a much lower temperature.

if my memory is correct, it melts around 1700 degrees.

Most steels will dark blue around 800 degrees.

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the header on my cat was glowing when i was using premium fuel... it doesn anymore now that i use regular.[img]i/expressions/face-icon-small-smile.gif[/img]