1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

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 Well-Known Member Premium Member Contributing Member

    Messages:
    2,573
    Likes Received:
    1,544
    Trophy Points:
    798
    Joined:
    Jun 18, 2016
    Gender:
    Male
    Occupation:
    Panel Beater, Spray Painter, Custom Fabricator
    Location:
    Adelaide
    My Bike:
    Yamaha's, FZR250 3LN3 1990, XT250TS 57R 1986, IT200L 43G 1984
    I am just trying to help you, maybe take a picture with the tank off then ?
     
  2. Andych

    Andych Well-Known Member Premium Member Contributing Member

    Messages:
    1,262
    Likes Received:
    834
    Trophy Points:
    448
    Joined:
    Oct 6, 2016
    Gender:
    Male
    Location:
    Sydney
    My Bike:
    1987 Yamaha SRX250, Honda 1975 CB400F
    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 Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    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 Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    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 Well-Known Member Premium Member Contributing Member

    Messages:
    1,262
    Likes Received:
    834
    Trophy Points:
    448
    Joined:
    Oct 6, 2016
    Gender:
    Male
    Location:
    Sydney
    My Bike:
    1987 Yamaha SRX250, Honda 1975 CB400F
    With the hose... where does it go to?????
     
  6. Federal Agent at Large

    Federal Agent at Large Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    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
     
    • Like Like x 2
  7. Federal Agent at Large

    Federal Agent at Large Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    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 :) )
     
    • Like Like x 1
  8. Federal Agent at Large

    Federal Agent at Large Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    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 Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    ... and here is the recording from this knocking sound...
     
  10. Rob1976

    Rob1976 Active Member Premium Member Contributing Member

    Messages:
    121
    Likes Received:
    70
    Trophy Points:
    53
    Joined:
    Oct 25, 2017
    Gender:
    Male
    Location:
    Adelaide
    My Bike:
    Hyosung gt250r
    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 Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    Rule out the breaks - its new pads and disk - with some squeezing sound on occasion - Not where the sound comes from
     
  12. my67xr

    my67xr Well-Known Member Premium Member Contributing Member

    Messages:
    2,573
    Likes Received:
    1,544
    Trophy Points:
    798
    Joined:
    Jun 18, 2016
    Gender:
    Male
    Occupation:
    Panel Beater, Spray Painter, Custom Fabricator
    Location:
    Adelaide
    My Bike:
    Yamaha's, FZR250 3LN3 1990, XT250TS 57R 1986, IT200L 43G 1984
    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 Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    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 Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    Brand new wheel bearings, break pads & disk - noise not coming from there
     
  15. Wozza

    Wozza Active Member Premium Member Contributing Member

    Messages:
    260
    Likes Received:
    148
    Trophy Points:
    148
    Joined:
    Mar 21, 2017
    Gender:
    Male
    Location:
    South Australia
    My Bike:
    GB250
    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 Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    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 Premium Member Contributing Member

    Messages:
    260
    Likes Received:
    148
    Trophy Points:
    148
    Joined:
    Mar 21, 2017
    Gender:
    Male
    Location:
    South Australia
    My Bike:
    GB250
    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"
     
    • Agree Agree x 1
    Last edited: Jan 14, 2018
  18. Federal Agent at Large

    Federal Agent at Large Member

    Messages:
    84
    Likes Received:
    22
    Trophy Points:
    18
    Joined:
    Oct 26, 2017
    Location:
    Western Australia
    My Bike:
    250 vlc Intruder 1990
    ok
     
  19. Andych

    Andych Well-Known Member Premium Member Contributing Member

    Messages:
    1,262
    Likes Received:
    834
    Trophy Points:
    448
    Joined:
    Oct 6, 2016
    Gender:
    Male
    Location:
    Sydney
    My Bike:
    1987 Yamaha SRX250, Honda 1975 CB400F
    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 Well-Known Member Premium Member Contributing Member

    Messages:
    2,573
    Likes Received:
    1,544
    Trophy Points:
    798
    Joined:
    Jun 18, 2016
    Gender:
    Male
    Occupation:
    Panel Beater, Spray Painter, Custom Fabricator
    Location:
    Adelaide
    My Bike:
    Yamaha's, FZR250 3LN3 1990, XT250TS 57R 1986, IT200L 43G 1984
    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
     

Share This Page