2006 LC4 going into 2003 bike

Discussion in 'Thumpers' started by meat popsicle, Aug 15, 2019 at 6:57 AM.

  1. meat popsicle

    meat popsicle Ignostic

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    I have a low miles 2006 LC4 to put into my 2003 640a. One big question so far:

    Engine has its SAS system. Do I only need to hookup an air hose to the airbox? My 03 ECU won't mind it?

    Attached Files:

    #1
  2. Diddly

    Diddly Bored of Directors

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    Your ECU is incredulous you would even consider hooking up the SAS.
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  3. Diddly

    Diddly Bored of Directors

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    I don’t recall the SAS having any connections to the air box. The carb bowl vent tube runs backwards up the subframe and terminates (alongside?) the air box.

    Vacuum that drives SAS and ECS is supplied by a barbed spur on the right hand, intake side of the cylinder. A short rubber hose comes off that vacuum fitting to a T splitter. One hose goes forward to the SAS, the other goes back to the ECS. (The carb bowl has a vent tube that runs back by the air box.)

    You might be the only guy who is actually trying to put the stuff on.

    IMG_4999.jpg
    #3
  4. Tseta

    Tseta Lost

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    You need to get rid of that SAS system ASAP.

    Cheers,

    Tseta
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  5. meat popsicle

    meat popsicle Ignostic

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    LOL - excellent start to a thread!

    I recall there being lots of folks who removed their supplemental air system, but why? Seems like a lifetime ago... so I dug a bit:

    https://advrider.com/f/threads/ktm-part-id.178833/
    Decel backfiring? I thought people paid extra for exhaust systems that did that. Here's a bit more collected:
    https://www.ktmforums.com/threads/the-dukes-secondary-air-system-sas.4095/

    I looked at the parts fische - the part I didn't get is the hose to a filter:
    https://www.trevorpopemotorcycles.c...ktm_fiche_finder&model=9703D1&group=C04584312
    I can get a filter on that intake or run it back into the airbox.

    So that's leaving it as is - removing it seems to be a bit of a bother (same link above). I'm pondering... but seems like there is little point in leaving it since it seems the catalytic converter it works with is elsewhere on the bike this motor came off of eh? I think I just need to remove it.

    I don't have the parts for this of course, and I want to install this motor and fire it up! But I think there's a way to disable it by plugging the vacuum port? I'll keep digging; suggestions appreciated.

    saved info: Did you put in the 583.36.024.000 PLUG SAS BORE and the 584.36.054.000 CU-SEAL RING 12 X 16 X 2 between the flanges.........?
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  6. Whodatschrome

    Whodatschrome Long timer

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    On my friend’s ‘05 640A, I cut that small diameter EGR exhaust pipe thingy off, pinched it closed, then welded (or braised, I can’t remember which) it shut. Then I chased down the rest of those crazy hoses and canisters. This was all less than two years ago.


    -EDIT-
    I snapped a pic of my friend’s ‘05 today. It shows where I cut that pipe off and cut the tabs off the bracket. I’d had rather had plugged it right at the exhaust manifold, but I was in a hurry and didn’t want to disconnect the exhaust header to do it.
    E274D380-CEEA-40CA-8705-1854208149E0.jpeg
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  7. Diddly

    Diddly Bored of Directors

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    I figured since the SAS introduces air into the exhaust to further combust unburned fuel, that could only lead to a hotter a exhaust pipe. (Who needs that...)

    The SAS adds clutter to the bike. But the ECS adds clutter AND kills second and third gear engine responsiveness. Removing it is free and effective. Think how much we spend on exhaust for more performance. Or change gearing (shifting compromises in bottom or top).

    If you remove the SAS:
    -some people leave / plug in place the metal tubing (mentioned above) to avoid creating exhaust leaks. Or,
    -remove the tube and replace with that plug and washer. I think Gunnerbuck(?) mentioned recently that he played with washers to make the exhaust flange press more on the plug and also used a dab of exhaust putty.
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  8. Diddly

    Diddly Bored of Directors

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    IMG_0144.jpg

    IMG_0145.jpg


    The right-hand exhaust flange has a bracket on which the SAS hangs. I think you can still buy the non-SAS bracket, or just grind the SAS bracket off the old flange. No going back!!

    IMG_5003.jpg
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  9. meat popsicle

    meat popsicle Ignostic

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    Sorry but I know not what this ECS to which you refer is. Hopefully not the TPS, which gives the fuel map its 3rd dimension.

    I'm putting this 06 engine on my 03 bike. I'm using my 03 BST so probably no ECS thingey.

    I've blocked the SAS tube and removed the solenoid; left the bracket as its not in the way. I routed the vacuum tube direct between the fuel pump and intake port. What do we call those things... nipples?
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  10. Diddly

    Diddly Bored of Directors

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    My fault, you said ECU - I was thinking ECS.

    My 05 had ECS. In second and third gear, the ECS slows advance of the vacuum actuated slide in the BST. (Kills the snappiness of the throttle response)

    The ECU is another valve type body with ancillary hoses and wiring plug:

    IMG_5006.jpg
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