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Help Weird knocking sound from below front end of tank @ low speed - Suzuki VLC Intruder

Discussion in 'Suzuki 250cc Twins' started by Federal Agent at Large, Oct 27, 2017.

  1. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

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    I am just trying to help you, maybe take a picture with the tank off then ?
     
  2. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    It is also confusing when you say that the idle speed goes up when you block the hose... that would normally mean it was a hose on the vacuum side of the carby... do you feel suction when you go to block it??

    As for the noise.... is your chain adjusted correctly? If the noise isnt there when stationary even when raising and lowering the revs it certainly wont be cam chain...
    Generally if it is a big end noise you can get the rattle by revving the engine and as the revs come down you will hear the bearing rattle... when there is no load on it..
     
  3. Federal Agent at Large

    Federal Agent at Large Active Member

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    Its not from the manifold - These two hoses is properly connected on the left hand side (this little hose comes out on the right hand side)
     
  4. Federal Agent at Large

    Federal Agent at Large Active Member

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    Hose: not manifold - and yes, its weird it goes up in idle when plugging it - I cant really feel suction (I guess it does, but its so little you wont feel it)

    Noise: Chain (meaning drive chain - sure is properly tensioned and straight wheel alignment)
    I have tried everything in the book replicating this knock sound while being stationed (Also tried (listening very carefully when going at 30+ km/h (nothing)
    Wonder if I perhaps could make an attempt to record this while driving really slow? - not sure - might try something out a bit later
     
  5. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    With the hose... where does it go to?????
     
  6. Federal Agent at Large

    Federal Agent at Large Active Member

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    Not 100% sure - will pull the tank again and trace it back to where its connected - Last I pull the tank I didnt disconnect any fuel lines and I were alone, so a bit tricky checking it properly - next time I will ensure my son (that I after all is trying to help out) bother to be with me - sleeping in, no real interests doing ****, while my head is about to explode being curious & tracking down the issue(s)
    Once Ive done this I'll post an update
     
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  7. Federal Agent at Large

    Federal Agent at Large Active Member

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    And its appreciated - hope it wasnt anything I said though - posting here is really me reaching out for some assistance and advice - so if I somehow managed to tick you or someone off (which would be a bit of mystery to me if I had), then please accept my sincere apology
    Tank will come off, these fuel line hoses is a mess dealing with by your own though - who on earth came up with the idea of connecting fuel lines coming in from the inside out (no way you can get to it unless you have 4 hands + a few beer and a dog to kick when things dont work out :) )
     
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  8. Federal Agent at Large

    Federal Agent at Large Active Member

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    Heres' what happens with the idle once I block this odd hose

    (shortly I will try to post something on the odd knocking sound (which on this occasion started to be persitant up to 40-50km/h (thats new) used to only occur coming to a near stop
     
  9. Federal Agent at Large

    Federal Agent at Large Active Member

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    ... and here is the recording from this knocking sound...
     
  10. Rob1976

    Rob1976 Active Member

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    I noticed in your video with the knock there was brake squeal and click always in the same order. I'd be checking for loose pads or front brake assembly. Or a stuffed wheel bearing.
     
  11. Federal Agent at Large

    Federal Agent at Large Active Member

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    Rule out the breaks - its new pads and disk - with some squeezing sound on occasion - Not where the sound comes from
     
  12. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

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    So is the sound coming from the left side, front cylinder, and the right side, rear cylinder ?
     
  13. Federal Agent at Large

    Federal Agent at Large Active Member

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    My feel is right side front(ish) - but it could come from the left side (front(ish)
     
  14. Federal Agent at Large

    Federal Agent at Large Active Member

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    Brand new wheel bearings, break pads & disk - noise not coming from there
     
  15. Wozza

    Wozza Active Member

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    sounds like its not idling right prob related to the hose.....this in turn is causing the knock, because engine is out of wack...
    could be the timing chain..could be piston slap, gudgeon pin rattle,primary drive slop, gearbox and a thousand other things..block of the hose(or find out were it belongs) bring the idle down and see if the knock noise changes or go's away....
     
  16. Federal Agent at Large

    Federal Agent at Large Active Member

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    So your 10c is to block this hose, turn down the idle in the hope it goes away or...?
    The core of my question is still what this hose do / purpose / connection point (if required) - just blocking a hose for fun and wait to see what happens is not scientific enough in my book - I like to know where things belong
     
  17. Wozza

    Wozza Active Member

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    na more like 2c but yeah ....diagnostics of a bike Im not familiar with via a forum is not the easiest thing to do....Alas in my 20+ years of forum reading my go to quote is
    "let being helpful be more important than being right"
     
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    Last edited: Jan 14, 2018
  18. Federal Agent at Large

    Federal Agent at Large Active Member

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    ok
     
  19. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    Until you can tell us exactly where the hose goes to it is hard to tell you what it is meant to do...
    I doubt it is a drain hose though mainly because your idle speed smooths out and drops when you block it off.
    I think @Wozza was saying either block the hose off or find where it goes which in turn should bring your idle speed down...
    Best to try and troubleshoot one issue at a time... and the hose is probably the easiest to do initially...
    But..... you are going to have to get that tank up and search out where the hose starts from first... otherwise we are all just taking wild stabs in the dark.
     
  20. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

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    How long does a tank take to get off?
    For the 3 or 4 minute's you spend doing it, you will soon get an answer
     

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