KTM 640 SM Exhaust modification

Discussion in 'Thumpers' started by Sycamore, Apr 21, 2006.

  1. Sycamore

    Sycamore d00b

    Joined:
    Mar 30, 2006
    Oddometer:
    1,697
    Location:
    Dubai, United Arab Emirates

    Exhaust thing turned out perfectly.

    The carb info on this site (thanks Creeper, Meat and everyone else concerned) is amazing. I punched a few 10mm holes in the back plate of the muffler, re-jetted carb to 152,5, raised the needle, reduced rear sprocket by 2 teeth, and now she is pulling like an ox, it's amazing. Or like a camel I should say. Better than having a new bike.
    I took it to a friend who tunes bikes for desert riding, he insisted on pulling off the part indicated in the pic (is that the snorkel?). Seems to be a heck of a lot more air going through, might be my imaginantion but I think i can actually hear the airbox sucking. But it's feels extremely good, not lean at all, smmoth acceleration all the way through.
    Anyway I could go on and on but suffice it to say I'm very happy.
    #61
  2. herobikes

    herobikes HE AINT HEAVY HES MY LC4

    Joined:
    Apr 28, 2005
    Oddometer:
    207
    Location:
    DOVER , NEW HAMPSTER
    Snorkel it is , jet accordingly with more airflow.
    #62
  3. lost1

    lost1 Adventurer

    Joined:
    Dec 7, 2003
    Oddometer:
    60
    glad things are working out for you. Some say leave the snorkel in and modify the side of the airbox. I removed the snorkel and opened a hole in the side of the airbox. was quite happy with the results.
    as for the sandstorms. that sand blasted my face so bad that I had to sit and wait in my tent for a couple days.
    Dubai is way too humid for me, better to move further inland. I know its hard to leave the airconditioners...

    i would bring you an an exhaust for your bike, but I don't know when I will be in the UAE next. THe camel may be a better courier at this point
    #63
  4. overlandr

    overlandr Dystopist

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    Camel Couriers rule!!
    #64
  5. overlandr

    overlandr Dystopist

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    Its the one where I have to wait for some spare space in a suitcase!:evil
    #65
  6. positionsize

    positionsize Been here awhile

    Joined:
    Jan 16, 2007
    Oddometer:
    103
    Location:
    Arizona, Florida and Philippines
    I belive Coughinhk has found the answer to modifying the European Silencer (N0N-Supertrap model)that is Stock on the 640Adv and 640SM delivered to Europe and Australia.:clap


    The link to his thread is HERE and quotes from his thread below



    Attached Files:

    #66
  7. positionsize

    positionsize Been here awhile

    Joined:
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    What came off

    Attached Files:

    #67
  8. positionsize

    positionsize Been here awhile

    Joined:
    Jan 16, 2007
    Oddometer:
    103
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    A pic of the 'finished' exhaust.

    Attached Files:

    #68
  9. tdv

    tdv Been here awhile

    Joined:
    Nov 25, 2006
    Oddometer:
    134
    Location:
    San Francisco, CA, US
    Kind of offtopic, but..

    Seeing how you guys are desperate for a good sounding exhaust :D, may be you'll be interested in the Twinfire Ti full exhaust for KTM LC4 (dual canisters) I have which is collecting dust. I'm pretty sure it'll fit years other than '01 - that's the one I had it on.

    It sounds awesome, worked very well on my bike.

    Sorry for the pic - the only one I could find.
    I'll make and send additional ones if needed.

    Make an offer :ear

    (I'm in the Bay Area, CA, US)

    Dmitri
    #69
  10. positionsize

    positionsize Been here awhile

    Joined:
    Jan 16, 2007
    Oddometer:
    103
    Location:
    Arizona, Florida and Philippines
    Thank for the offer tdv. I have already installed a Staintune Slip-on and I am very happy with it. I have also performed the standard performance mods suggested by so many on this site. My 640a not only sounds better but the bike has noticeably more power through the entire range of throttle.

    My reason for posting the above information is to hopefully help out some others wishing to make pennytech mods to there stock Euro/Australian exhausts.

    If I had this information six months ago, I would have done the mod and probably saved my self $499.00 USD I spent on the Staintune.
    #70
  11. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,566
    Location:
    Circumlocution Office of Little Dorrit
    FYI,

    KTM changed the distance between the exhaust flanges with the Hi-Flo Head on 2003, so I believe anything with a Hi-Flo head will not fit that exhaust that worked with the lo-flow head. Too bad, because I might have been interested...
    #71
  12. tdv

    tdv Been here awhile

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    Nov 25, 2006
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    134
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    San Francisco, CA, US
    Thanks for the info! I'll pass it on to potential buyers.

    Dmitri
    #72
  13. Raw_force

    Raw_force Dansker!

    Joined:
    Apr 6, 2008
    Oddometer:
    49
    Location:
    Esbjerg Denmark
    have the same model exhaust onmy KTM. DAM something...
    made a a few mods on mine aswell, took out the sparkarrestor drilled 6 10mm holes on the outside of the S-tube and rejettet my carb from 142,5 to 155.
    it sounds a lot better now but it feels the same. I haven't had a chance to really rip loose yet, but i'll let you know.

    just out of interrest did you remove the S-pipe or just drill around it?


    i thought about removing everything inside the exhaust an and installing a steel net tube with new wool around it...like the duke modification.

    will it have enough resistance or will it be too much?

    thanx.
    #73