OHH MAN!?! DR650 header glowing red

Discussion in 'Thumpers' started by Dirt McGirt, Sep 19, 2010.

  1. Dirt McGirt

    Dirt McGirt Adventurer

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    Well I guess I should start by saying that I had been experimenting with which jets and mixture settings worked best for the old DR. This was while it was alot hotter and alot more humid here. I got it to where it seemed to be working about as good as I could get it.(pretty darned good)

    Now the weather has changed and it is a whole lot cooler and less moisture in the air.

    I have the 170 main jet, clip set at the #4 from the top of the needle slot. I had the mixture screw set at between 3/4 and 1 turn out.

    The instuctions that came with my extended mixture screw from kientech said to set it between 3/4 and 1 1/8 turns out.

    The paperwork that came with the dynojet kit says 2 1/2 turns out, which seems to be way too rich in everyone's opinion, including mine.

    Now the issue, I just came out of my dad's house after letting the bike sit for over an hour. The bike was cold enough to need to be choked to idle.

    After less than 2 minutes(of idling) the header was glowing red, never in 4 years have I seen this happen.

    This made me real nervous, but once I fattened up the mixture it seemed to be back to normal.

    Anybody had this happen before?

    Is it semi-normal?

    Is it easy to fry a motor this way?

    Anything I should be worried about?

    Anybody care to give me your thoughts on this? Thanks guys Dirt
    #1
  2. jtwind

    jtwind Wisconsin Airhead

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    take this over to thumpers and the dr650 thread and you'll have better luck with the right answers
    #2
  3. MarylandStrom

    MarylandStrom Been here awhile

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    It happened all the time on my old Yamaha WR400 when I let it idle. I never liked the idea of it glowing, so I tried not to idle very long. But in my opinion it is pretty normal on big bore four strokes.

    I think a lot of people don't notice that their thumpers are glowing red because they seldom ride at night. The glow can be seen in daylight but obviously not as easy as in the dark.
    #3
  4. Bobthebiker

    Bobthebiker not normal

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    I've seen the glowing exhaust thing. idling excessively does that. basically what it is, is that you have all that exhaust heat building up, and no airflow to help carry said heat off, so the pipe begins to heat up and glow.

    doing this isnt GREAT for your engine, try if you can to keep air flowing over it. overheating it may cause damage you dont even want to realize can be done so easy.
    #4
  5. Jrmobb

    Jrmobb Been here awhile

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    glowing is normal no worries. Happens on all my bikes. Like stated previously, most people just never ride at night so they dont see it.
    #5
  6. techforlife

    techforlife CDI REPAIR

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    +1 normal.....won`t hurt a thing,no airflow cooling the header.....mine will glow red when idling and the oil teperature is only 200 degrees,so the engine itself is not really hot..

    B
    #6
  7. KneeKicker

    KneeKicker Long timer

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    First time I saw the "glowing pipe" I freaked too I had a 98 YZ400f and thought something was wrong. MY DRZe will do it too if it idles too long but not as quick as the YZ did.
    #7
  8. Flatulator

    Flatulator Banned

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    pop open the hood on a 4 cyl car ... with a header exhaust (not a cast manifold) ... (at night) .. the exhaust is all glowing a dark red in there

    looks kinda evil ... and cool

    ... and normal

    you might not see it in daytime as well ... but at night you will
    #8
  9. Dirt McGirt

    Dirt McGirt Adventurer

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    Thanks for the replies guys, I feel a little better now.

    I have 13k on this bike and just less than half of the miles have been at night. I have never seen this happen.

    I think that I had it running extra lean and this contributed to the glow.

    Once I richened the mixture it went away immediately.

    Seems to be alright. Runs still, that's always a good thing:D .

    Thanks again for chiming in guys, Dirt
    #9
  10. gplassm

    gplassm Been here awhile

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    Don't worry, unless the color starts approaching *white*.
    #10
  11. rallyhound

    rallyhound Macho stud guy

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    HMM INTERESTING.

    Just went for a 30 mile ride, came home and let the bike idle for 30 minutes.

    Exhaust header didn't glow a bit.
    #11
  12. Motomantra

    Motomantra Registered Lurker

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    Yea, Some of these guys are lost.
    No, it shouldn't be glowing. On the other hand, an air cooled engine needs air flow. Don't let it idle for long.
    #12
  13. JensEskildsen

    JensEskildsen Long timer

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    Why would you let a aircooled engine idle for 30 minutes?

    Do you run it without oil aswell, to check for knocking sounds? :D

    Headers CAN glow red, they do get awfully warm very fast, some do, some dont glow.

    Run a low rpm/throttle sparkplugcheck, it the plug is white or gray, adjust the CO screw, that could help.
    #13
  14. diesel critter

    diesel critter Adventurer

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    fuel air ratio, spark and/or valve timing can affect how hot the exaust gets. Even cast iron manifolds can glow red, they shouldn't, often its a timing problem, or perhaps in the case of some mcycles, the timing at idle isnt really what it should be for optimal idling, cuz thats not what motor bikes are for!
    #14
  15. Brendan J

    Brendan J Pfft

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    Did it look anything like this ???? And this is in the daytime.

    [​IMG]
    #15
  16. I GS 1

    I GS 1 I 90S I

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    <a href="http://www.flickr.com/photos/geckoracing/2845807930/" title="Glowing turbo and exhaust mainfold by i90si, on Flickr"><img src="http://farm4.static.flickr.com/3184/2845807930_aa20575389.jpg" width="500" height="375" alt="Glowing turbo and exhaust mainfold" /></a>

    Pic of my son's car on a dyno
    #16
  17. rallyhound

    rallyhound Macho stud guy

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    .


    I let it idle for a half hour simply to test the glowing header theory as discussed here.
    My Vapor temp sat right at 265 deg which is 30 less than on a hot day at 70mph.
    #17
  18. Seth S

    Seth S Will _____ for _____

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    Classic Saab 900 Turbo...






    [​IMG]
    #18
  19. rallyhound

    rallyhound Macho stud guy

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    My evo manifold gets like that but only with the anti-lag switched on
    #19
  20. Flatulator

    Flatulator Banned

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    no ... you're just showing your inexperience

    although they might not typically visibly glow during the daytime when strock from the factory ... they are always close to the temp where they will glow ... and anything that pushes them towards running a little hotter or leaner.. (aftermarket mods - a fiddly owner making changes - slow running on hot days - working the engine hard - slightly clogged carb jets from crud buildup - excessive idling) ... will mak'em glow ... (on LOTS of diff engines)
    ... not on all ... and not all the time

    I have an ATV that is stock ... it never normally glows ... until I do certain hard-working activities (pushing/hauling a heavy load for a while)... only then ... at night (so you can see it better) .. it glows ...
    ... and always runs great.

    ... and ... it pretty much has to be a single wall pipe (to glow) ... lots of street bikes have dual wall headers ..., partly to keep fussy streetbike riders from freaking out (with a glow) ... and partly to preserve their precious chrome
    #20