KTM 640 Winter Project

Discussion in 'Thumpers' started by CSF, Oct 13, 2012.

  1. juames

    juames Have Fun, Don't Die!

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    I installed a FCR-41 MX on mine and it was fairly straight forward, and I actually got better fuel economy then BST. My BST was ready for an over-haul like yours...lots of worn parts. I'll get between 350-400km before reserve of regular riding. Definitely make the bike more snappy, and feel quicker.
    #61
  2. biensur22

    biensur22 Been here awhile

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    I'll have to pick up one of those oring kits today when I go out there.

    I didn't do a write up, mainly because there's nothing to write. I started with a 170main, 40pilot and an erm needle from sudco. Because the carb I used didn't have a bell on the air box side I had to enlarge its diameter by inserting a 1/2" piece of radiator hose over the top of it, now the air box boot fits snug. It mounted right into the intake boot without problem. Only issue I had were my cables, but that's because my bike was setup for a dellorto phm single cable carb that use different fittings. So I had to modify them for the throttle housing on my bike, but your throttle housing should be plug and play.

    All accounts indicate that the fcr will improve your mileage as well as performance, tho I only completed the install 2 days ago and haven't laid down enough track to test it myself. Like I said, mine was complicated because of my particular year 640, but even then the only hiccup was the cable.
    #62
  3. philosobrad

    philosobrad problem_solvent

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    Just awesome. I picked up an '01 Monday night in Kansas City, the PO had decided to part it out, so I'm in the process of putting it back together. I'm 90% there, but does anyone know where this hooks up:

    [​IMG]
    #63
  4. Low594

    Low594 Adventuring Creep

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    It hooks to the EPC assembly found on Euro bikes, that appearantly neutered the power in 2nd & 3rd gears, I believe! US models its open to atmospheric air, but tends to suck alot of dust into the upper portion of the diaphragm. Either in the BST40Bible or one of MotoLabs thread there is a K&N part number for a filter to help it out!
    #64
  5. CSF

    CSF Been here awhile

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    #65
  6. philosobrad

    philosobrad problem_solvent

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    Thanks!

    Spent the last hour trying to start it. Even with a new battery it spins over too slow to catch. This is using the manual decomp, letting the decomp go after two good spins. The second I let go of the decompressor, it slows to a stop. Aggravating, Looking like I purchased a heap. I managed to get one ear shattering backfire with the decomp pulled in.
    #66
  7. juames

    juames Have Fun, Don't Die!

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    Need new battery maybe? Need to spin pretty quick to fire up.
    #67
  8. philosobrad

    philosobrad problem_solvent

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    Went back out and kicked the hell out of it for about 10 minutes and she fired. Now starts easily with the starter, weird. May have an auto decomp on the way out. Sounds great, and I'm proud to join the 640 ADV ranks. Thanks and sorry for the highjack....winter project proceed :)
    #68
  9. Low594

    Low594 Adventuring Creep

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    I would look at the threads dealing with the starter sprague and starter itself. My starter shaft seal went out and the starter would fill with oil! It still worked, but it wasnt happy!
    #69
  10. CSF

    CSF Been here awhile

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    Low594 - cable tube length is 30.5" from plastic receiver on the throttle to the nuts at the carb. There's about 3" of bare cable at each end that go from the nut to the carb and same for the receiver to the throttle tube. (hope that makes sense, if you need more info just ask)

    philosobrad - Glad you got it started. I've had a few of those "this bike is junk and I should have just bought a new one moments", in the end I think I'll have a lot of hours into the bike but not a whole lot of money and I hope at the end of this a really awesome bike. But, If its all worth it is up to you.

    On that note here are the worn carb plastics (each piece is around about $40 to replace :cry ):

    [​IMG]

    [​IMG]

    [​IMG]
    #70
  11. juames

    juames Have Fun, Don't Die!

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    Ouch! Check with a company called Motolab, I've heard the sell rebuild kits. Not sure of the price though.
    #71
  12. CSF

    CSF Been here awhile

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    juames

    I checked with him, seemed like a great resource. His parts are about the same price I can get here, then when shipping from California and customs are worked in... I don't think it would really work out for me. Too bad, he seemed to really know his stuff.
    #72
  13. juames

    juames Have Fun, Don't Die!

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    Right...
    #73
  14. biensur22

    biensur22 Been here awhile

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    FCR! If you're spending over $100 to rebuild the bst, might as well double down and improve the performance.
    #74
  15. gunnerbuck

    gunnerbuck Island Hopper

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    That piece does not hook up to anything, it is a carb vent that contains a filter screen and it normally hangs downward beside the carb...
    #75
  16. Low594

    Low594 Adventuring Creep

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    #76
  17. wrk2surf

    wrk2surf on the gas or brakes

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    the symptoms are there...

    Nice bike LOW..

    I will be gettin mine cleaned up here in the next two months myself..
    #77
  18. Low594

    Low594 Adventuring Creep

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    Thank you!
    #78
  19. juames

    juames Have Fun, Don't Die!

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    #79
  20. CSF

    CSF Been here awhile

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    juames - Thanks for the heads up, just looked through the thread. All of the carbs are gone... such is life. I'll eventually find one. I may take a trip to the some of the motorcycle wreckers this summer. And I'll keep an eye on kijiji and ebay...

    New parts are on their way, so for now I'll have to suffer with a well sorted and rebuilt BST.
    #80