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Sweetwater 220 Fuel Vent Issue

RogerA Member Posts: 1

I'm looking for some advice regarding what appears to be fuel vent issues. 2012 Godfrey Sweetwater 220 Pontoon. After about an hour or so the Honda 90hp vtec just dies like its out of gas. We have found that when we loosen the gas cap an excess amount of air pressure comes out then the engine will start and run fine for about another hour or so. The vent runs directly beside the filler mounted to the side of the boat. I can't find any low places or obstructions on the vent hose. Any advice greatly appreciated!

Also looking for a Ski Rope Tow Bar.


  • Missed_Again
    Missed_Again Member Posts: 4
    I have the exact same problem with a 2016 18' Sweetwater and 40 HP Honda.  I contacted Godfrey and they sent me a diagram of the fuel system but no advice.  When it happens and I crack my gas cap it sounds like an inhale rather than exhale.  I think the Net Positive Suction Head drops to a level where we get vapor lock but thinking this does not solve the problem.  After you look at the fuel system diagram IMHO I think the government has made such demands on escaping vapors it is impossible to have the problem solved.

    Missed Again 
  • proftomda
    proftomda Member Posts: 6
    Did you ever find a fix for your condition?  My 2018 has a huge release of pressure when I remove the cap and I actually got sprayed in the face with gas it was so strong.  
  • ajwerden
    ajwerden Member Posts: 1
    Hi. Any word on what works? Just had a 2013 lock up unable to suck fuel and then start working after opening the gas cap. Is there a valve somewhere that I need to clean or replace?
  • perrydb3
    perrydb3 Member Posts: 2
    I just purchased a 2013 18' Sweetwater pontoon and I think I'm having a problem with fuel venting system similar to the previous descriptions. Motor runs for about 15 minutes then quits like it's out of fuel. I turn off the key, then restart the engine and it runs fine for another 15 minutes or so, then quits again.  This only happens when I'm out on the water, not when I'm running the motor in my yard. I see a lot of hoses connected to the main fuel fill hose, plus a carbon canister.
    Has anyone figured out this system and solved the problem? Thanks, Dean
  • CraigModerator
    CraigModerator Member, Moderator Posts: 25
    Just my attempt to help explain what's going on.  

    OK, where to begin (I apologize cause this will probably be a bit long and more info than you wanted), the fuel problems exists with any boat manufactured from 2011 to 2019 and it has to do with new EPA mandates (our government at work) on marine fuel tanks and how they now have to not allow hydrocarbons into the air.  Boat manufacturers purchase fuel systems from fuel system manufacturers that offer approved fuel storage systems.  These manufacturers designed the EPA compliant fuel systems for boat manufacturers to use on their boats.  Prior to 2011, fuel systems were vented at the or near the cap, allowing hydrocarbons (gas fumes) into the air.  The new system is a sealed system capturing and processing hydrocarbons, this system is more complicated and adds more parts (which, of course, adds more points of failure).

    2010 and Earlier Vented Fuel System

    2011 and Later Diurnal Fuel System

    Slow fueling, splash-back and air sucking into the tank when the cap is opened to fill problems can often come from a venting issue – common with with the inlet control valve – P-trap or fill (see diagram above).  Also, you cannot fill these tanks completely as they have an air gap purposely designed in them to allow for expansion.  Sometimes the Carbon Canisters can also get clogged, but that is usually with older boats

    Here's a link to a pretty good video on the subject from Perko:

    Now comes the update, the diurnal system has been modified on the 2020 model year boats to a less complicated design (welcome to the slow motion of government change).  Maybe the newer design will eliminate the problems of its predecessor:

  • perrydb3
    perrydb3 Member Posts: 2
    Craig, Thank you for your explanation!  In the new diagram (2020) have the carbon canister and P-trap now been completely eliminated from the requirements?
  • CraigModerator
    CraigModerator Member, Moderator Posts: 25
    That's a really good question Dean.  I have been trying to find a diagram that includes the "inner" workings but to no success so far.
  • Liguorimike
    Liguorimike Member Posts: 1
    The fuel inlet valve has failed on my sweet water 3386 pontoon. Backsplash and Burp when I try to fill. Tank is currently empty. I’ve read a few posts, etc. how do I access and remove this valve?

  • CAMPboat2286
    CAMPboat2286 Member Posts: 1
    Seems like the fuel system fail is a long standing problem.  We just purchased our 2017 Tri 2286 have put about 46 problem free hours and just have had this vapor problem.  have searched lots of sites and this has been going on without a shown problem.  Any answers yet what to do?
  • [Deleted User]
    [Deleted User] USAPosts: 0 admin
    Here's a picture with labels of a typical Godfrey fuel tank. Hope this helps

  • [Deleted User]
    [Deleted User] USAPosts: 0 admin
    Diurnal, or self contained venting fuel systems are newer than the canister system and often times requires a venting fuel cap also. The venting space in the tank is self contained which makes for a finite space instead of pushing the fumes constantly out of a filter like a canister venting system. This small space is generally why we as consumers do not like the diurnal system because it makes for slow fuel pumping into the tank. Hopefully ya'll can see where I'm heading with this one so I'm going to leave it at this. =-) 
  • tnikles
    tnikles Member Posts: 9
    none of this stuff makes any sense
    Translate to English Please
    and explain how to fix it