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exhaust header glowing cherry red

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hey guys , i have a 2002 drz400s , the bike has the 3x3 mod and a full fmf exhaust with powerbomb.   recently purchaced the bike., and the engine would not even idle with the choke off.  the carb was very gunked up, i pulled it apart, the pilot jet was plugged. cleaned the carb.  and got the bike running farly decent.  good ecceleration, have alot of popping on decel.  after idling for a few minutes the header pipe glows red. . i am also looking to rejet the carb to compensate for the exhaust and 3x3 mod.  any sugestions on what jetting setup would work best.. and what could be causing the popping and the exhaust to be getting red after idling. i appreciate it.

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For an exhaust pipe to glow red you'd have to be running pretty lean, I suggest you not run it anymore until you fix the carb. If it's doing it idle, it's time to look at the pilot circuit again.

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Thank you for your response , any idea of what jetting I should run? Or a certain kit that would work well for these mods . Thank you

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I run the JD jet kit and Keintech extended fuel screw on my DRZ, works great and highly recommend it. Comes with multiple main jets, a 25 pilot jet (one step up from stock), adjustable needles, and Allen head float bowl screws (the stock Phillips head screws strip out fairly easy).

Edited by Wisconsinite762

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Durobro , you should have taken down the particulars of what was in your carb when you cleaned it . Jet sizes , needle type and make of carb , would help a lot to find out what is going on . I would hold off on buying anything untill you are sure you need it , greg

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With no air flow past the pipe to cool it, it is going to glow red.  I would expect the carb to already be rejetted.  Decel popping is normal.

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A glowing red pipe is not abnormal when the bike idles for a bit.comfirm your pilot circuit( check the FAQ's)

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 thank you , yeah i should have taken down the particulars. i believe it has been rejetted once before. i am pulling the carb tomorrow to replace the diaphram because it was in bad shape . so when i have it apart, i will give you guys the sizes of the jets that are already in there.   i know there is a extended pilot screw already installed.   and to the other responses about the exhaust turning red; as soon as i took it down the street, it cooled down.  i just wanted to make sure so i didnt burn up the exhaust valves.

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hey guys , i have a 2002 drz400s , the bike has the 3x3 mod and a full fmf exhaust with powerbomb.   recently purchaced the bike., and the engine would not even idle with the choke off.  the carb was very gunked up, i pulled it apart, the pilot jet was plugged. cleaned the carb.  and got the bike running farly decent.  good ecceleration, have alot of popping on decel.  after idling for a few minutes the header pipe glows red. . i am also looking to rejet the carb to compensate for the exhaust and 3x3 mod.  any sugestions on what jetting setup would work best.. and what could be causing the popping and the exhaust to be getting red after idling. i appreciate it.

 

zero air flow = red hot head pipe...Installing a jet kit won't change that..

 

popping on decel = normal for open pipe...

 

Correct jetting will however help with performance... 

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More than likely jetting is the culprit. However an exhaust cam that is installed a tooth advanced can also cause a pipe to glow. It opens the valve too early so the exhaust gases are at higher temps. Check your cam timing.

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I wouldnt worry about the glowing header, it's normal for bikes to do that at idle my Yfz also does it. As for popping on decel, that means your lean I'd go up a few sizes on the main and see how it is then.

Edited by five_pointe_o

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Mine never glows red. Only time it did is when i wrecked the head and the cams ate the journals. Its was red red! After £600 head its fine now. Check your valves cams etc

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Yeah, it should not glow red. This is a DRZ, not a yzf, it's not a high strung mx bike. Look into the jetting, air filter /air leak, valves/timing etc...

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{style_image_url}/attachicon.gif ImageUploadedByThumper Talk1382817629.655147.jpg

Header pipes on almost any newer bike will glow red if left to idle without any air cooling them off

the DRZ is not a "newer" bike (no offense) ... It came out almost 15 years ago, and this is the street legal version with lower compression and CV carb. No reason the header should glow, especially if it has a free flowing muffler that will get rid of the spent gasses much more quickly.

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the DRZ is not a "newer" bike (no offense) ... It came out almost 15 years ago, and this is the street legal version with lower compression and CV carb. No reason the header should glow, especially if it has a free flowing muffler that will get rid of the spent gasses much more quickly.

its new enough and with a cv carb that runs very lean it will eventually start to glow red.the pic of the bike I posted is a 03vstrom1000. Its not that new either but still glows if left to idle to long without air cooling it off

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its new enough and with a cv carb that runs very lean it will eventually start to glow red.the pic of the bike I posted is a 03vstrom1000. Its not that new either but still glows if left to idle to long without air cooling it off

I mentioned the CV carb because the higher performance dirt only model has an FCR. Obviously any carb can be jetted lean, but at least with an FCR, it has a pump that'll cool things down once in a while

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I can only see my pipe glow when it's dark and it's pretty faint on my yfz. If it's like cherry red in day light Yeah something is lean on the idle circuit.

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