Where are the gas tank air vent holes?


Information and questions on GL1100 Goldwings (1980-1983)
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dwight007fchr
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Where are the gas tank air vent holes?

Postby dwight007fchr » Sun Jun 09, 2013 8:51 pm





It seems that my gas tank is not allowing outside air to enter as the fuel pump is trying to pump gas. In the picture above, you can see the tank top with the two holes on the bottom. There are also two squarish holes higher up, but with the rubber gasket sealing the top, air cannot get in.

How is air supposed to enter the gas tank?

Many thanks.
dwight



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themainviking
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Re: Where are the gas tank air vent holes?

Postby themainviking » Sun Jun 09, 2013 8:56 pm

I am not an expert in these matters, but I would think - through the gas cap.
It ain't about the destination - it's all about the journey

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dwight007fchr
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Re: Where are the gas tank air vent holes?

Postby dwight007fchr » Sun Jun 09, 2013 9:26 pm

The Man Viking......I agree.....seems the vent should be through the gas cap. However, the outside top portion of the top has no pin holes in it, and when you flip it over, there is a big rubber gasket that seals tight along the top surface of the gas tank. No pin holes under the top near the rubber gasket. So, I am stumpped as to where the air vent hole is.

Surely someone will know....hope to hear from them.
Maybe I just need to take a hammer and 16 penny nail and drive a hole into the top?

dwight

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Johnyy Smoke
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Re: Where are the gas tank air vent holes?

Postby Johnyy Smoke » Mon Jun 10, 2013 4:22 am

The factory gas cap is the vent- it is spring loaded to remove vacume as it bulds inside the gas tank. You should be able to suck air thru these vents. if you cannot, try soaking it in white vinegar overnight ,then use lots of compressed air and carb cleaner to clear it.
Clogged gas cap vents can lead to lots of frustrating problems if not repaired-your fuel pump will most likely fail after a time.
Carbs may overflow with gas.
Not a difficult fix either, Rgards, Johnyy

dwight007fchr
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Re: Where are the gas tank air vent holes?

Postby dwight007fchr » Mon Jun 10, 2013 8:29 am

Johnny......thanks for the comment. The thing that I dont understand is that these two vents which are spring-loaded go upward to two side vents. But with the rubber washer on the top, how in the world does air get past the rubber washer and into the vent holes? Perplexing. Maybe I need to slice the rubber washer so there is an opening??????

I will go and try blowing air thru the openings.......and go ahead and soak it and flush out as you say.

thanks.
dwight

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80-GL100-INT
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Re: Where are the gas tank air vent holes?

Postby 80-GL100-INT » Mon Jun 10, 2013 5:41 pm

dwight007fchr wrote:
83WingGasTankTop004.jpg


It seems that my gas tank is not allowing outside air to enter as the fuel pump is trying to pump gas. In the picture above, you can see the tank top with the two holes on the bottom. There are also two squarish holes higher up, but with the rubber gasket sealing the top, air cannot get in.

How is air supposed to enter the gas tank?

Many thanks.
dwight



If you look real close under the lip of the cap just outside of the gasket there are 4 vent holes. When you put on the cap the little tabs are spring loaded inside and they release the valve to allow the tank to breath.
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dwight007fchr
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Re: Where are the gas tank air vent holes?

Postby dwight007fchr » Mon Jun 10, 2013 8:13 pm

80GL1000int.......Dern if you are right! I had to get up and go check this out when I read your post. Yep, there are 4 small stamped holes on the outer edge which did not catch my eye when I was looking before. So, now I just need to do a deep soaking and blow some air thru them to get them working better.

Many thanks for showing this to me!
dwight

tunaboy
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Re: Where are the gas tank air vent holes?

Postby tunaboy » Mon Jun 10, 2013 9:30 pm

I read somewhere that guys were drilling a small vent hole in the gas cap. (1/16''). If the cap seals off and this is bad for the fuel pump would the small hole be a good option to maximize the life of the pump? I don't like the idea having a vent hole in the cap as the bike sets for the winter but I don't want to replace a fuel pump sooner that needed.
What do you think?
Thanks,
Tuna

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Re: Where are the gas tank air vent holes?

Postby tunaboy » Mon Jun 10, 2013 9:42 pm

Just wondering if there is a cheap aftermarket gas cap that will fit? If so I would buy one and drill a hole in it and see how it works out.

dwight007fchr
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Re: Where are the gas tank air vent holes?

Postby dwight007fchr » Mon Jun 10, 2013 10:28 pm

Tunafish.....Well, first I will try just soaking and using air to blow out the openings. And these vent holes are super small, so sitting over the winter is no issue......but I guess one could just run a piece of tape over the outter 4 pin holes when storing the bike over the winter......but then if you forget to remove, you have other issues.
dwight

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80-GL100-INT
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Re: Where are the gas tank air vent holes?

Postby 80-GL100-INT » Mon Jun 10, 2013 11:07 pm

http://www.ebay.com/itm/1981-Honda-GL11 ... b5&vxp=mtr

They can be found cheap enough to play around with.
If "WE THE PEOPLE" don't defend our rights...Who will?
"Government's first duty is protect the people, not run their lives."...Ronald Reagan

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ned
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Re: Where are the gas tank air vent holes?

Postby ned » Thu Oct 31, 2013 10:02 pm

Hi all,
Just came across this post. Had the same problem and I thought that I've managed to clean the cap by using an ultrasound cleaner. It kind of worked.

This is my theory on how the thing works or should work.
a. The tank holds pressure (gas builds up pressure). This is also useful to prime the pump after standing overnight. So, keep your petcock shut and open it before you try to start the thing. If you have a transparent fuel line you will see the fuel rush towards the pump.
b. the cap should hold a little bit of vacuum, but not a lot. It should not fight the pump. I often open the cap momentarily to release vacuum.

My problem is that after a bit of a ride, I often see that the fuel filter is almost empty and the fuel flow is slow. I have no air leaks in the line, the filter is new and I started with the lines filled with fuel and a tank full of gas. So, what happened ... where is the air come from?

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80-GL100-INT
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Location: Bedford, In.
Motorcycle: 1980 GL1100I Interstate (current)
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1981 CB 750 Custom
1976 CB 750 Super Sport (punched to 900)
1986 Kawasaki 440 LTD
1974 Suzuki 550
1986 Kawasaki Ninja 600 (First Street Bike-way back in '88)
Contact:

Re: Where are the gas tank air vent holes?

Postby 80-GL100-INT » Mon Nov 04, 2013 7:40 pm

Only theory...There is not air in the fuel line, there is a lack of fuel in the line. Which means the vent holes are not allowing enough air in compared to the amount of fuel going out. When you ride up to the gas station to get gas, and open the cap it's not so much pressure as it is vacuum. Care still needs to be taken as the vacuum can still allow fuel to be blown out as the air rushes in to fill the void.
If "WE THE PEOPLE" don't defend our rights...Who will?
"Government's first duty is protect the people, not run their lives."...Ronald Reagan

http://www.powdercoat.tk/

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petesgoldwing
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Re: Where are the gas tank air vent holes?

Postby petesgoldwing » Sat Jun 27, 2015 1:23 pm

Gas Cap Vent


:idea: :idea: The factory gas cap is the vent- it is spring loaded to remove vacume as it bulds inside the gas tank. You should be able to suck air thru these vents. if you cannot, try soaking it in white vinegar overnight ,then use lots of compressed air and carb cleaner to clear it.
Clogged gas cap vents can lead to lots of frustrating problems if not repaired-your fuel pump will most likely fail after a time.

Read more: viewtopic.php?f=4&t=17439#ixzz39IWY3Xyy

I did this and so far it seems to work :D :D :o ,( most be at least over night soaking )

Pete




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