Vented gas cap for 97 GL1500
MarkusK
Posted 12/14/2014 10:41 AM (#81666)
Subject: Vented gas cap for 97 GL1500



Member

Posts: 16
0
Location: Owasso, OK 74021
Hey folks!
I have a '97 GL1500 with a CSC FII. I mounted a Summit Racing 4 gallon fuel cell in the bike trunk with a gravity feed to the bike fuel pump cover. Problem is, the bike's tank cap is not vented. This prevents the fuel from the trunk cell from draining in to the main when the main gets low enough to expose the opening in the fuel pump cover.
Does anyone know where I can get a vented cap for the factory Wing tank? I'm hoping this will solve the problem, as for now I have to ride with the cap slightly loose to provide the venting.
Thanks.




(6_Tank install_1.JPG)



(9_Right fuel splice_2.JPG)



Attachments
----------------
Attachments 6_Tank install_1.JPG (130KB - 0 downloads)
Attachments 9_Right fuel splice_2.JPG (71KB - 0 downloads)
Top of the page Bottom of the page
CCjon
Posted 3/7/2015 1:16 PM (#83243 - in reply to #81666)
Subject: Re: Vented gas cap for 97 GL1500



Extreme Veteran

Posts: 348
10010010025
Location: NWHouston
Not sure I understand. Are you saying you currently have a non-OEM gas cap on the GL1500?
The factory gas cap is vented and I have an extra one if that is what you are looking for.
CCjon

By the way, great job of installing aux tank and plumbing. Very clean and neat.

Edited by CCjon 3/7/2015 1:18 PM
Top of the page Bottom of the page
MarkusK
Posted 3/7/2015 4:22 PM (#83248 - in reply to #81666)
Subject: Re: Vented gas cap for 97 GL1500



Member

Posts: 16
0
Location: Owasso, OK 74021
Thanks CCjon! To clarify, I do have an OEM cap on the Wing tank. The problem may be the plumbing for the Aux.
When I fill-up, I fill the Aux first, so I can see it running into the Main. Then I fill the main to the bottom of the filler neck, at which point I install the Main OEM cap. Then I go back and top off the Aux. The problem that is occurring is that as the gas is being used, it runs from the main first, and isn't automatically draining from the Aux. The gas level will go down in the main and when the bottom of the Aux line is exposed, nothing happens. It's as though there's a tension holding the fuel back. If I slightly turn the Main cap, allowing for passive venting, the fuel will then drain from the Aux into the Main.
As the upper photo shows, I have a vent line coming from the top of the Aux, but that doesn't appear to be assisting with the problem.
Once I get the carb rebuild finished, I'll go at it again and see if I can figure this out.
Thanks for the feedback.

Edited by MarkusK 3/7/2015 4:23 PM
Top of the page Bottom of the page
CCjon
Posted 3/7/2015 4:45 PM (#83249 - in reply to #81666)
Subject: Re: Vented gas cap for 97 GL1500



Extreme Veteran

Posts: 348
10010010025
Location: NWHouston
It appears that you have three (3) vents on the aux tank, right? the top hose, the blue vent on the right and the small vent on the fill cap itself. Should not be a problem on that side.

As I understand it, the 1500 gas cap allows pressure to build up in the tank, only allowing it to vent once a certain pressure is reached. However have been warned to not fill the main tank and then park in the garage. Gas fumes will fill the space.

Sounds like the OEM gas cap is holding in too much pressure, not enough enough to open the OEM release, but enough to inhibit the gravity flow from your aux tank? If there is not much fall in the flow from the aux to the main, gravity is not much help. If that is the case, raising the level of the aux tank or adding a fuel pump might be the only solutions.

Have an 5 gallon aux tank in the back of my Champion Escort. Though it sits lower than the main tank, by using a fuel pump, have not had any issues transferring fuel.

Reread your first post.. so the aux tank is much higher than your main tank, right?

Edited by CCjon 3/7/2015 4:48 PM
Top of the page Bottom of the page
MarkusK
Posted 3/8/2015 10:48 AM (#83259 - in reply to #81666)
Subject: Re: Vented gas cap for 97 GL1500



Member

Posts: 16
0
Location: Owasso, OK 74021
Yes, the Aux is in the 1500's trunk, significantly higher than the Main. The only vent in the Aux is the hose on the left. The right side only has a cap. I considered that the hose vent on the Aux would be enough to allow pressure venting for the flow from the Aux, but I guess not. The whole idea of this location was so I wouldn't need to employ another fuel pump.
Like I said, once I get the carb rebuild finished and put the bike back together, I'll go at it again. It just may turn out that I'll need to install a pump. If so, got any suggestions?
I'll post updates as I go.
Top of the page Bottom of the page