red hot pipe

[tnl]

My new (1 day old) yz 450f's exhaust pipe gets red hot within seconds after start up by the cylinder head. Does this sound like a carb. jet problem? Gonna take it in first thing next business day. Till then, I'll just have to admire my toy sitting in the garage. Grrr...........

[bluerider450]

yeah most likely its running way to lean

[Indy_WR450]

Put in a 48 pilot or a 50 if it is cold out. The bike is lean. It should take a minute to get it read hot idling.

[Harry Paratestes]

If it's getting red hot in seconds it may well be lean, so check for intake and exhaust leaks. Check that the fuel screw is in the ball park(1 1/2 turns out). If it`s that lean, how hard is it to start. Try running it through a few gears gently and see how it runs, it will pop on deceleration if it is lean. It`ll also pop if their is an exhaust leak. It is highly unlikely that if it runs there will be any danger of engine damage.

Or it could be that it is like all the the other YZfs, that`s just what they do.

[tnl]

The bike starts ok and it did "pop" couple of times while deceleration. Thanks for the input!

[sirthumpalot]

Back away from the head pipe... there is nothing to see here... back away..

Seriously, the headpipe will glow read, this is normal. Ignore it. Jet the bike so that it runs good, do not ever change your jetting to try to change how the head pipe glows. ?

[yz426onNOS]

Back away from the head pipe... there is nothing to see here... back away..

Seriously, the headpipe will glow read, this is normal. Ignore it. Jet the bike so that it runs good, do not ever change your jetting to try to change how the head pipe glows. ?

?????

Use the search noob!!!!!?

[PimpdYZ]

My headpipe heats up very quickly, but doesnt ''glow red''... could he have meant ''really hot'' instead of ''red hot''??? ??

[x2stroker]

Mine turns red hot as well, but is running fine. As long as it's not running lean, you should be ok....

[grayracer513]

People new to these bikes usually report this right after the first time they start the bike in low light conditions, like around dusk. The "seconds" that it tales to turn red depends on the ambient light, not your jetting. Like Sir Thump said, make it run right and don't worry about the pipe. The headers on the YZFs are only about .035-.040" thick, and titanium at that. The red at idle is normal, and so, BTW, is radiator boilover after 3 minutes idling.

Four strokes are like sharks. They need to keep moving. ?

[rakkno]

I read from someones post that the 450 is jetted lean from the factory. I spoke to a guy at a local shop and he recommended re jetting, but not sure if that is for where I ride.. ?

[stainlessTT]

People new to these bikes usually report this right after the first time they start the bike in low light conditions, like around dusk. The "seconds" that it tales to turn red depends on the ambient light, not your jetting. Like Sir Thump said, make it run right and don't worry about the pipe. The headers on the YZFs are only about .035-.040" thick, and titanium at that. The red at idle is normal, and so, BTW, is radiator boilover after 3 minutes idling.

Four strokes are like sharks. They need to keep moving. ?

I agree with grayracer513. If you start the bike up in a low light garage for example you will see red within seconds. I noticed that on my bike when I first got it, didn't think anything was wrong. Its thin titanium hit by exhaust right out of the head, its gonna get hot fast. I've put around 80hrs on my 04 450, with no problems at all, no jetting changes or anything. ?

Only thing I don't like is how close that header pipe is to the radiator, I been meaning to fabricate a heat sheild, but I have more impotant things to do. ?

[Jetsprint2]

I am with StainlessTT, in my low-lit garage the pipe gets red-hot very quick. My 450 runs great with the stock header and jetting. Can't wait for the snow to melt! ?

[tnl]

It's positive feedback from older yz'ers like yourself that keep newbies like me away from the dealers with inexperienced questions like this. By the way, you're exactly right. Went to the dealer today and was told pretty much what you commented.

Thanks!

[tnl]

Stay away from the light!!!! I really meant that the pipe glows orange.

[stainlessTT]

I think we all should wrap our header pipe with some of that header exhausht wrap thats made for hot rods and such. I think it would help the motor run a bit cooler. What do you guys think? And a heat sheid to stop cooking the coolant in that radiator, I think would help also.

[sirthumpalot]

Unless the header was designed for that much heat, it's not a good idea to wrap it. I wrapped a header on my truck when I was a kid, after a couple of months it crumbled into a pile of metal flakes. Apparently the warning in the instructions to not wrap it was correct, it couldn't take the heat. ?

[grayracer513]

I think we all should wrap our header pipe with some of that header exhausht wrap thats made for hot rods and such. I think it would help the motor run a bit cooler. What do you guys think? And a heat sheid to stop cooking the coolant in that radiator, I think would help also.

Heat in or out of the exhaust has already left the engine, so raising or lowering the temperature in the header won't affect the engine temperature. Furthermore, I don't think I understand how insulating the head pipe to prevent it radiating heat away would reduce the engine temperature on a vehicle with its engine out in the open, instead of trapped under a hood.

As far as a heat shield goes, the amount of heat that would actually be transferred to the radiator by radiation at a standstill is hardly significant. The engine will be heating the coolant many times faster, and lack of air flow over the radiators is a much bigger issue at that point. How much do you think the bottom tank can absorb from the exhaust with a 15 MPH breeze blowing over the head pipe?

[studruss]

I'm New to the thumper scene and just got a 2001 scene426F (thanks Scott). I started the bike in my garage yesterday for the first time and about %$#@ !!! when i noticed the cherry red head pipe. I did a search here and found this to be a coming thing. Thank god for this site. It sucks to be a newbie but we all have to start someware.

Thanks to all at TT,

Russ

[markyz450]

Four strokes are like sharks. They need to keep moving. ?

the 11th commandment. no air movement = no cooling, radiators are useless w/o air moving through them.