Results 1 to 5 of 5
  1. #1

    gas tank venting problem?

    When removing the cap from the gas tank, it seems to be building air pressure. I'm assuming there's a vent tube plugged somewhere. 97 slt 780 premix.

  2. #2
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    near Toronto, Canada
    The factory venting system uses a pressure release check valve that can hold around 2PSI before venting.

    Mild positive air pressure inside the fuel tank (1-2 PSI) is OK and normal. Extreme air pressure is not.

    There is also a vacuum relief check valve that is supposed to allow air into the tank even with minimal vacuum. So the fuel tank should never have any significant vacuum.

  3. #3

    Join Date
    May 2014
    Paris, TN
    On an SLT the fuel tank pressure relief valve is located near the front seat latch. The hose should be mounted in a rubber grommet. if your tank is building pressure that valve needs to be replaced. the hose it is on should also have a tee in it with another valve hanging in the hull. that valve will be the vacuum relief valve.

  4. #4
    I'm pretty sure it's over 2psi. Shoots out like a cork gun just glad it's on a chain would've lost it in the lake. I will check those valves thanks

  5. #5
    I like pipes. I love boost Mr. GP1800's Avatar
    Join Date
    Jun 2010
    Milwaukee WI
    I have found the pressure valves to pop around 2.5 PSI. Believe it or not, that is enough pressure to blow the cap off.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. 07 yamaha fxho gas tank vent
    By Seakid in forum Yamaha PWC Performance (4-stroke)
    Replies: 1
    Last Post: 04-28-2015, 10:41 AM
  2. 01 Virage gas tank vent?
    By badnblack55 in forum Polaris PWC Performance
    Replies: 3
    Last Post: 06-18-2013, 11:56 PM
  3. Gas tank problems?
    By nickflo7 in forum Polaris Open Discussion
    Replies: 13
    Last Post: 04-02-2013, 12:07 AM
  4. gas tank venting issue
    By flowmasterman in forum 2-Stroke Performance
    Replies: 3
    Last Post: 08-12-2011, 10:22 PM
  5. MSX 150 -Gas Tank Won't Vent
    By Koodat in forum MSX/Matrix
    Replies: 2
    Last Post: 07-06-2010, 03:32 PM

Posting Permissions

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