The BST-40 Bible

Discussion in 'Thumpers' started by laramie LC4, May 31, 2008.

  1. bikemoto

    bikemoto Tyre critic

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    b, check the slide guide, too. My BST-equipped Triumph wore the slide guide, allowing the whole slide and hence jet needle to float fore/aft, sawing the new needle jet oval in short order.
  2. drdave_2006

    drdave_2006 Been here awhile

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    I put some solder in the hole then re drilled it to the correct size. But would be better to replace with new parts. And this is why it is hard to tune properly.

    [​IMG]
  3. laramie LC4

    laramie LC4 flying something...

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    id be hesitant toward doing this. the dr650 and the Lc4 are 2 completely diff monsters. i would be surprised if it truly was better than the stock. i personally think that most issues that are had with this carb can be solved with adjusting fuel/air, proper idle jet, correct clip position, and a good Main. i dont know that anyone can really be able to tell the diff between diff needles considering how forgiving this carb is to begin with. just just my opinion though and if anyone has any info to the contrary, please speak up....

    laramie :beer
  4. laramie LC4

    laramie LC4 flying something...

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    we have a diff slide (assuming that is what you are showing) and solder would not work, it would just melt it....

    laramie :beer
  5. BLINKER 152

    BLINKER 152 mudlover

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    speaking of needles... just took my mikuni off the ktm 640 e to find my needle is shot probly from the vibration wear thing. well they are currently on backorder from ktm... :puke1 of course i am scheduled to leave on TAT in 2 weeks. money saved, time off work:clap , kid at the grandparents,ect. i need a needle for my mikuni bad, very bad asap. my mental sanity may depend on it:huh . any body out there got one settin round the toolbox. i will pay you:deal . any body know where else i should look to get one asap. any body smarter than me know about if i can use one from a dr650 ? would the needle be the same in their mikuni if i cant locate ktm part.? whos got an extra needle for my katoom????? any one? send me a pm please.:freaky ktm part #584.31.034.6G5
  6. bikemoto

    bikemoto Tyre critic

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    He's showing the needle jet (aka emulsion tube).
  7. NordieBoy

    NordieBoy Armature speller

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    He did ask "There are no "performance" needles like JD for BST?"

    DJ do do one for the BST...
    Looking at their site it seems they only do kits for race bikes though so the 640 is left out :D

    :deal :freaky

    Someone needs to do an mx_rob and test all the needles with an a/f meter hooked up.

    The KTM needle is as good as you can get for the DR utilizing the stock airbox/exhaust.
  8. NordieBoy

    NordieBoy Armature speller

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    That's the needle jet.
    It's brass usually.
  9. meat popsicle

    meat popsicle Ignostic

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    Am I missing something?

  10. laramie LC4

    laramie LC4 flying something...

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    Ok, duh....now i see it. this guy....

    [​IMG]
  11. NordieBoy

    NordieBoy Armature speller

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    That's a bit low. Throwing facts into the mix :(

    Has someone tested all of them with an AF meter and got optimal settings for each?

    Think of it as a project for this afternoon.

    We'll wait...
    :freaky :1drink
  12. laramie LC4

    laramie LC4 flying something...

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    i think you should get one that...... :loco

    considering the cost of an AF meter, all of the needles, and the time, i doubt that anyone has ever even thought of it (maybe thought, but thats as far as they got) nor has anyone considered it a worthwhile endeavor. like i said before, i havent even heard of anyone using a diff needle other than stock. i may be wrong, it wouldnt be the first time, but until someone shows me otherwise ill stick with my origional statement. you should be able to do all the tuning you need and can feel (seat of the pants) with the jets.

    laramie :beer
  13. clintnz

    clintnz Trans-Global Chook Chaser

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    Gave my BST a strip down & clean up last night. I've had some high fuel use lately, then on the last ride it got really good mileage so I thought it was time to give the carb some lovin...

    The slide & slide guide were worn, but not too sloppy. The needle jet & lower needle looked fine, the upper needle where it goes through the slide was quite worn, maybe 1/3 of the way through, like the pics earlier in this thread. The hole in the slide for the needle was also worn. The float height was way high, which is strange 'cos I'm sure it was good last time I checked at 50K km. I haven't run it yet, hopefully I got that float level right but I think I did it as per the manual.

    So I've ordered a new needle, needle jet, slide & guide & a new diaphragm. With all that done hopefully she'll be good til the 150K km mark :D I'll take some pics when I pull it to put in the new parts when they arrive.

    Cheers
    Clint
  14. meat popsicle

    meat popsicle Ignostic

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    cugino pegaso was the bloke who had one of them there custom Ti needles from Factory Pro. I think he did the chart I photographed above. Here are the only posts searching finds from him on it:

    http://www.advrider.com/forums/showthread.php?p=1113534#post1113534
    http://www.advrider.com/forums/showthread.php?p=1398517#post1398517

    Did you see his stuff on KTMTalk Laramie? Maybe this is his handle over yonder: http://ktmtalk.com/index.php?showtopic=84160
  15. CaptTurbo

    CaptTurbo Long timer

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    Dude, just read about what has been done ... before saying silly stuff like that. MX_Rob did exhaustive tests with needles and jets which saved many of us lots of time, money, and trouble. I followed him through it all and made many of the changes with him and can tell you that the best you will ever get with the DR650 short of fuel injection is the FCR39-MX.

    You don't need an AF meter or to buy needles that you don't need because all the work has been done for you.

    Oh and PS: You are WRONG! Way wrong. Now, scamper off and read about it all. :rofl
  16. Nico

    Nico Save the USA

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    Did I miss something, or are you unaware that this is a thread about the BST40 in an LC4? Or were you too busy scampering about to read that part of the thread? (the title, that is.)
  17. laramie LC4

    laramie LC4 flying something...

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    well.....thank you for your input. considering it has nothing to do with the bike we are talking about i'm not sure how it really applies. if someone has done extensive testing, with multiple needles, using an AF meter, then good for them. that still doesnt change the fact that it has NOTHIN in similarity to the 640. im glad that someone else (like me) was able to help you with your problems.

    im more than willing to read a post about a LC4-640 where all the work has been done for me. can you provide a link? if there is someone else out there willing to put themselve out there for the masses to ridicule and bash on, then hell, maybe im wasting my time....but from the guys post, he specifically requested a AF meter and multiple needle testing.

    wow!!! im glad that you were able to point that out for me. i luv it when people point out my short comings, especially without providiing any proof of their claims.

    just to give you a little background, i dont even have this carb anymore. i replaced it 2 years ago with a FCR-39. i made this post for those who still had it, and needed help with working on it. i did it out of the "kindness" of my heart. not for fortune or glory, but simply to help others out because i remember the frustration, anxiety, and nervousness i felt when i first attempted this stuff. i do my best to answer people questions based upon my experience and hope that it is helpful. i never claimed to be a"mikuni carb pro for ALL models." so when ever you want to do something else as productive for the masses other than critisize, id be glad to hear it. until then, why dont you piss off. im drunk, pissed off, and dont feel like defending myself to some internet troll anymore. :flip

    laramie :beer
  18. stephano

    stephano Long timer

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    I'd start calling every KTM shop I could find on the internet and check Sudco and carbparts.com and any other carb parts place I cant think of right now. Of course, just make sure your getting the same part.
  19. 666

    666 Agnostic and Orange

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    Laramie,
    No good dead goes unpunished

    You are the man.
  20. laramie LC4

    laramie LC4 flying something...

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    amen brother! :clap