/ Register

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

Solved ZXR250c "metal grinding" noise at 10krpm

Discussion in 'Kawasaki 250cc In-line 4's' started by Seapop, Sep 19, 2017.

  1. Seapop

    Seapop Well-Known Member Premium Member Contributing Member

    Messages:
    102
    Likes Received:
    45
    Trophy Points:
    213
    Joined:
    May 14, 2015
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    Kawasaki ZXR250C 1993
    Hey guys
    Recently my bike has a terrible metal grinding like noise/metal tapping screach at 10000rpm exactly. It's not a shallow engine whine it's definitely substantial and noticeable. Sounds like a grinder. More pronounced when laying off the throttle after revving to say 12000-13000rpm and the revs come back down to 10k. It's so painful to listen to =(. If I hold the throttle at 10k it's constantly there. Tapping grinding tapping grinding screaching tapping grinding.
    11000rpm nothing there.
    9000rpm nothing there.
    I'm really hoping it's just resonance from vibrations or maybe a loose bolt? I don't know where to start.
    Could it be valve clearances out of SPECK? never done a check and adjustment before.
    Bike is a 93'. 28500kms on the clock
    Cheers
     
    Seapop, Sep 19, 2017
    #1
  2. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

    Messages:
    4,313
    Likes Received:
    2,383
    Trophy Points:
    898
    Joined:
    Jun 18, 2016
    Gender:
    Male
    Occupation:
    Panel Beater, Spray Painter, Custom Fabricator
    Location:
    Adelaide, South Australia
    My Bike:
    Yamaha's , 1990 FZR250R 3LN3 , 1986 XT250TS 57R , 1984 IT200L 43G, 1976 IT400C 510
    Timing chain's can stretch and the timing chain tensioner's can go out of spec.
    Might be worth taking the rocker cover off and check for any grinding mark's inside the rocker cover.
     
    my67xr, Sep 19, 2017
    #2
  3. Cbuzz

    Cbuzz Well-Known Member Dirty Wheel Club

    Messages:
    142
    Likes Received:
    58
    Trophy Points:
    233
    Joined:
    Mar 30, 2017
    Gender:
    Male
    Location:
    Australia
    My Bike:
    ZXR250A
    This +1 !
     
    Cbuzz, Sep 19, 2017
    #3
  4. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

    Messages:
    4,732
    Likes Received:
    2,874
    Trophy Points:
    943
    Joined:
    Mar 18, 2014
    Location:
    Sydney NSW
    My Bike:
    FZR250R 3LN6
    Yep the zxr does not have a guide over the timing chain so if it is stretched or the tensioner is worn out the chain will rub against the cam cover.

    If you pull the cam cover off, make sure you inspect the chain guides down in the chain tunnel too.
     
    Linkin, Sep 19, 2017
    #4
  5. Cbuzz

    Cbuzz Well-Known Member Dirty Wheel Club

    Messages:
    142
    Likes Received:
    58
    Trophy Points:
    233
    Joined:
    Mar 30, 2017
    Gender:
    Male
    Location:
    Australia
    My Bike:
    ZXR250A
    Yep, if its that bad it means the cam chain is very loose. If it slips a few teeth kiss your engine goodbye.

    Get it sorted Asap !!
     
    Cbuzz, Sep 19, 2017
    #5
  6. Seapop

    Seapop Well-Known Member Premium Member Contributing Member

    Messages:
    102
    Likes Received:
    45
    Trophy Points:
    213
    Joined:
    May 14, 2015
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    Kawasaki ZXR250C 1993
    Cheers guys. Guess I'll have to take a look.
    Complete newbie here so if there are marks inside the cover what is the next step?
    Might be worth taking it to a mechanic as much as I'd like to avoid it... But if it's a pros job then I probably wouldn't trust myself.
     
    Seapop, Sep 20, 2017
    #6
  7. Cbuzz

    Cbuzz Well-Known Member Dirty Wheel Club

    Messages:
    142
    Likes Received:
    58
    Trophy Points:
    233
    Joined:
    Mar 30, 2017
    Gender:
    Male
    Location:
    Australia
    My Bike:
    ZXR250A
    Either the cam chain tensioner has gone out of spec or your cam chain has stretched. If it's rattling around that much I'd change both of them.

    Confirm exactly what's making the noise first. Could be something totally unrelated :lolsign:
     
    Cbuzz, Sep 20, 2017
    #7
  8. Murdo

    Murdo The Good Doctor Staff Member Contributing Member Ride and Events Crew

    Messages:
    6,399
    Likes Received:
    4,786
    Trophy Points:
    1,148
    Joined:
    May 4, 2013
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Tamworth, NSW
    My Bike:
    1937 Royal Enfield 250, CF Moto 250 V5, Honda's XL250, CBR250, FT500 plus a few others.
    Also check for things like loose bolts on heatshield of muffler. Sometimes a loose piece of bodywork can rattle at a certain revs.
     
    Murdo, Sep 20, 2017
    #8
  9. Seapop

    Seapop Well-Known Member Premium Member Contributing Member

    Messages:
    102
    Likes Received:
    45
    Trophy Points:
    213
    Joined:
    May 14, 2015
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    Kawasaki ZXR250C 1993
    Have had problems with a tensioner on a Balius before that was making rattling noise at idle this one is more at 10k and it's a high pitched grinding noise sounds like a metal grinder through a steel pipe. Almost sounds like I'm blaring the horn on the bike the whole time..
    Guess I'll check the rocker cover and loose bolts . Cheers
     
    Seapop, Sep 20, 2017
    #9
  10. ShaneP

    ShaneP Well-Known Member

    Messages:
    2,574
    Likes Received:
    1,101
    Trophy Points:
    798
    Joined:
    May 12, 2014
    Gender:
    Male
    Location:
    Yeppoon
    My Bike:
    Yamaha FZR250 speed bike, Yamaha YZ/WR250F, Kawasaki ZX2R, Honda VTR250, DR350 (x 3.5), a couple of prototypes and whatever else.
    Check that the horn isn't resonating, if that's the sound. But if it's grinding, there's good reason why everyone is suggesting the cam chain. Other checks might be the water pump, coil mounts on the frame or loose baffling in the muffler, as well as the suggestions above. But the cam chain is the place to start - I believe a chain or belt can get a wave pattern based on speed and sprocket diameter, meaning it might sprape in one place at one speed.
     
    ShaneP, Sep 24, 2017
    #10
  11. Seapop

    Seapop Well-Known Member Premium Member Contributing Member

    Messages:
    102
    Likes Received:
    45
    Trophy Points:
    213
    Joined:
    May 14, 2015
    Gender:
    Male
    Location:
    New Zealand
    My Bike:
    Kawasaki ZXR250C 1993
    Bang on the money there
    Finally got around to getting it to a mechanic as I was, overseas at the time. Turns out it was some loose bits in the headers and exhaust.flanges.
    Basically took it apart to put it back together for an easy fix. No new parts required.
     
    • Like Like x 2
    • Winner Winner x 2
    Seapop, Mar 28, 2018
    #11
  12. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

    Messages:
    4,732
    Likes Received:
    2,874
    Trophy Points:
    943
    Joined:
    Mar 18, 2014
    Location:
    Sydney NSW
    My Bike:
    FZR250R 3LN6
    I get resonances from the right pillion peg sometimes
     
    Linkin, Mar 28, 2018
    #12

Share This Page