Page 1 of 2 12 LastLast
Results 1 to 10 of 17

Thread: Bit of an odd bubbling noise...

  1. #1
    Junior Member
    Join Date
    Oct 2013
    Posts
    16

    Bit of an odd bubbling noise...

    So I was doing an oil change yesterday and while draining the swingarm, I heard a constant bubbling sound. I traced it, as best as I can tell, to the fuel pump area. It seemed like a steady sound of air leaking into the tank but there was no sign of any fuel trading places with it.

    I searched the forum and only came across one other post asking a similar question and relating it potentially to a faulty fuel pressure regulator but there were no replies to it. I can understand if the regulator is failing to hold pressure and bleeding it back into the tank, but that shouldn't result in air being introduced into the system. I thought one option may be the tank vent valve being blocked causing a vacuum in the tank, but I tested the drain line and its clear (got a nice little octane buzz in the process ).

    My bike is a little stumbly around the 3000 RPM range but I have some troubleshooting planned to address that, just in case that may be connected.

    Any thoughts from the experts?


    Extra details:
    2008 XB12ss
    12,000'ish miles
    K&N filter
    Stock Exhaust & ECM
    94 octane (Ethanol free)

  2. #2
    Senior Member
    Join Date
    Jan 2016
    Posts
    502
    See if the noise goes away when you remove your gas cap.

  3. #3
    Senior Member Cooter's Avatar
    Join Date
    Dec 2012
    Location
    Crawling up your skirt
    Posts
    6,359
    Probably just the gas in the tank cooling off while the bike sits during its oil change and pulling in air through the vent like it's supposed to. Meh, you have other things to worry about than worry about that.

    What Outlaw said in different words
    Last edited by Cooter; 05-10-2019 at 04:59 PM.

  4. #4
    Senior Member
    Join Date
    Mar 2015
    Location
    Phoenix, AZ
    Posts
    1,019
    I've had 2 bikes that boiled fuel and it usually is a very faint bubbling, almost hissing sound. Its similar to when you heat up water on the stove, and the boiling just start. If its not negative pressure building in the tank, I'd check for overheating 2nd.

    On my SS it was the rear head sensor that was failing, and the bike was overheating. The 1125 was just a hot beast. LOL

    In some cases it will push fuel out of the breather tube and you'll see it dripping on the ground on the LH side of the bike.
    Last edited by 34nineteen; 05-10-2019 at 05:14 PM.

  5. #5
    Junior Member
    Join Date
    Oct 2013
    Posts
    16
    Thanks guys.

    34, what were your indicators of the failing heat sensor?

  6. #6
    Senior Member
    Join Date
    Mar 2015
    Location
    Phoenix, AZ
    Posts
    1,019
    Quote Originally Posted by Fishtank View Post
    Thanks guys.

    34, what were your indicators of the failing heat sensor?
    Boiling fuel, bike felt warmer than normal, and the fan wasnt turning on after shutdown.

    When I grounded the wire that normally went to the heat sensor, the fan turned on, so I realized it was likely the heat sensor.

  7. #7
    Junior Member
    Join Date
    Oct 2013
    Posts
    16
    Quote Originally Posted by 34nineteen View Post
    Boiling fuel, bike felt warmer than normal, and the fan wasnt turning on after shutdown.

    When I grounded the wire that normally went to the heat sensor, the fan turned on, so I realized it was likely the heat sensor.
    My fan does seem to be working, it stays on for 2-3 seconds after a ride and its not that hot up here yet, 60-75*F. I'll look into the wiring diagram, take some temperatures and do some digging on it.

  8. #8
    Senior Member Lusiphur's Avatar
    Join Date
    May 2015
    Posts
    367
    I overfilled my tank for the first time ever the other week.

    Man, these things sure do make a ****load of noise and stink like hell while it's cooling off when that happens.

    You can actually see the gas sloshing around, almost like waves on a beach.
    Jack-O-Lantern
    2006 Buell XBRS LightningBolt
    http://www.buellxb.com/forum/album.php?albumid=129

  9. #9
    Senior Member
    Join Date
    May 2016
    Location
    Central Soviet state of new jersey.
    Posts
    1,760
    Don't feel bad, I did the same thing last week.

  10. #10
    Senior Member Cooter's Avatar
    Join Date
    Dec 2012
    Location
    Crawling up your skirt
    Posts
    6,359
    Sooo, a guy named FishTank is worried about a bubbling noise?



    SharkBait! Moohaha!



Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •