1. Guest,
    We need good tech writers that are willing to help out here at ZL-OA. If you like taking photos of jobs as you perform the steps on your repairs, have historical ads/documents from old magazines, or any else you think belongs in the Technical Library than you might be able to help. Send a private message to Furchin, Mudrunner88, Chris, Jarney, Wuputt, or Markus56 and we can lead you in the right direction to get started.
    Dismiss Notice

Noisy gas cap buzzing.

Kappdaddy Sep 28, 2013

  1. Kappdaddy

    Kappdaddy Member

    5
    0
    11
    My ZL900 gas lid makes some serious noise. Possibly a worn hinge? I put a small piece of foam to under the lid to dampen it some. Tried a thin piece of card board slid under hinge pin. Still vibrating like crazy... Even drowns out the sweet sound of the engine at certain RPMs. Any one else experience this? Any luck resolving it? Thanks.
     
  2. Kappdaddy

    Kappdaddy Member

    5
    0
    11
    Just saw links to similar threads. Saw good tips to trouble shoot source.
     
  3. R. J.

    R. J. Senior Member

    7,821
    291
    128
    :hello: I think I seen a thread on this. Inside the cap assembly are small breathers or channels that sort of shrink up & start a buzzing noise. Also the small screws on the under side work loose. I put small nylon washers under my screws.
     
  4. SandstoneSmitty

    SandstoneSmitty Well-Known Member Supporting Member

    664
    1
    51
    My ZL9 had the tank buzzz. The only fix is new rubber tank mount bushes. You will need 3: 1 under seat & 1 for each side. The system is the buzz, the root cause is the vibration.
     
  5. R. J.

    R. J. Senior Member

    7,821
    291
    128
    :hello: I also replaced the fuel tank rubber grommets. I bought OEM but you can match them up at a hardware store. The quality may not be as good as OEM.
     
  6. MikeC

    MikeC Senior Member

    452
    8
    103
     
  7. MikeC

    MikeC Senior Member

    452
    8
    103
    Im really hoping this is the problem. The noise this bike makes, and it's not till about 5000 rpm caused me to pull over. I thought the thing was going to destroy itself. My tank mounts don't "feel" loose at all. I taped up the underside of the doghouse and spray glued some cloth as I could easily feel and hear that vibration with it removed. I mean I thought the tranny or engine broke off a piece or something. I'll know if it was the doghouse when it stops raining.
     
  8. Trojan441

    Trojan441 Active Member

    289
    10
    28
    I saw some spec's and can't believe they produced a 900cc motorcycle with an 11 litre tank capacity!
     
  9. Ducky Dog

    Ducky Dog Active Member

    177
    21
    38
    My gas cap was buzzing at about half tank
    when full it was ok
    Its due to the tank resonating
    new tank bushings will help and add some foam under the hump
     
  10. MikeC

    MikeC Senior Member

    452
    8
    103
    I might fill the hump with Great Stuff foam. When I had it off, I could reproduce that buzz by slapping it. Its just like a tuning fork.
     
  11. MikeC

    MikeC Senior Member

    452
    8
    103
    Just emptied a half can of Flex seal under the doghouse. Finish it off after that coat dries. That noise is ridiculous. I can't see a tuning fork making the same noise covered in flex seal, but this one might. Is there a fix for this that I missed? 20180824_195231.jpg
     
    Last edited: Aug 24, 2018
  12. MikeC

    MikeC Senior Member

    452
    8
    103
    Since its black anyway, I might cut a thin sheet of rubber and contact cement it on the front most angled part as that piece of plastic is just so prone to vibration.
     
  13. Ducky Dog

    Ducky Dog Active Member

    177
    21
    38
    I put some foam under the dog house hinge pin that helped some but,,,,
    On mine its the gas cap itself and that the tank is prone to harmonics when less than half full
    foam under the tank will help along with new mount bushings
    adding a thin rubber strip under the cap seal will keep the catches stay tight
    thats what I had to do to mine and I still get a faint buzz when gas is low
     
  14. Harriminator

    Harriminator Senior Member

    755
    128
    138
    Meanwhile having a ZL10-tank on my 9, I had the same buzzing on the 9-tank before; when I remember well the cap is fixed at the rear with a thin metal bar so I drilled the holes of the holder on the tank and the cap a little bit larger and put some small plastic sleeves in them fitting the bar diameter - and the rattle was gone...:laughing7:
     
  15. MikeC

    MikeC Senior Member

    452
    8
    103
    Ok, this ALL makes sense when I force it down at certain speeds it goes away.
     
  16. Raf900

    Raf900 Member

    22
    7
    13
    Check the rubber on the tank mounts . I once left one off on the side of the tank and my cap buzzed loud. found it on the driveway and put it back in place. No buzzing. I also have disabled the vent in the cap better flow, did that in the ZRX tank as well. If it is way out of sync on carbs it can compound the problem. That black stuff looks like it plugs the vent to me.
     
  17. MikeC

    MikeC Senior Member

    452
    8
    103
    I taped off the vent, but do you know what is meant by put a thin rubber strip under the cap seal? I believe this is my answer, but not sure where to put it. Under the chrome cap OUTSIDE the doghouse? Inside under the rubber seal that is already there?

    The flex seal did help some, but the are multiple additives to all this buzzing. A firm push down on the cap stops MOST of mine.

    I do have the rubber mounts, I'll try and get some, but they don't seem too bad.
     
  18. Raf900

    Raf900 Member

    22
    7
    13
    You are getting vibration thru the tank from somewhere . Do you have the rubber support in place under the tank? Isolating the tank from the frame will stop the buzzing. If it has direct contact it will make that noise. I have a thick rubber under my cap where the two locking prongs are, you have to hit it hard to lock , but it is a good tight and isolated seal. Disable the vent the tank will vent much better.
     
  19. MikeC

    MikeC Senior Member

    452
    8
    103
    You lost me on disabling the tank vent... how will that get better flow?
     
  20. MikeC

    MikeC Senior Member

    452
    8
    103
    I made a few rubber wedges and put 2 under the chrome cap and 2 between the doghouse and tank and that noise is gone. Just thought I'd share more I found. Someone had the heat shields off at one point and reinstalled them without lock washers. The gap left left those things rattle away when you hit the right note. Also the spring shield around the rear brake line had rotated putting it in contact with the muffler, again at the right rpm singing loud. I've got 1 left I haven't been able to find, but I will. Any un-tightened bolt and this motor has a resonant frequency for it. I think it's something with the fan....I remember reading about something... OH and one last thing every time I would turn a tight right turn, there was a noise and vibration like you wouldn't believe. I figured it was definitely a bad front wheel bearing, but it had no play when I lifted it off the ground. It was a twisted front fender the tire treads were strumming the fender. Loosened the bolt and it returned to its normal form. This thing has more noise I swear, but i still love it! The ZL9 was the first bike I rode and I had forgotten what attracted me to begin with. There is just something about it I like better.
     
    Last edited: Aug 26, 2018

Share This Page