Gas tank breater hole : Gas tank sealer

[posplayr]

This is an example of the location of the gas tank breather hole. I believe what happens is that as the air inside the gas tank heats up it expands and pushes the gas out of the filler. With this hole the air gets to the filler and so it doesn’t try and push the gas out. Anyway you will get tank overflow if this is plugged.

IF YOU DO A GAS TANK SEALER MAKE SURE TO POKE OUT THIS HOLE OR YOU WILL LIVE TO REGRET IT

[Ranger]

Now I'm told.. 4 days after I sealed it and its fully cured. Looks like I know what I'm doing today.

[tkent02]

Now I'm told.. 4 days after I sealed it and its fully cured. Looks like I know what I'm doing today.

You can just drill a hole anywhere in that area if you can't find the original hole. A little bigger hole is OK, too. Hopefully you haven't put gas in it yet?

[Ranger]

You can just drill a hole anywhere in that area if you can't find the original hole. A little bigger hole is OK, too. Hopefully you haven't put gas in it yet?

I think I'm ok, I stuffed the hole
I just have it mocked up on my bike, I havent put my inline fuel valve on yet so no gas.

[jhicok]

You can just drill a hole anywhere in that area if you can't find the original hole. A little bigger hole is OK, too. Hopefully you haven't put gas in it yet?

i need to do this...what side of the tank does the hole go? right or left as im sitting on it?

[tkent02]

Right side so it's up when the bike is on the sidestand. As high as you can go without hitting the top of the tank.

[posplayr]

You are correct. All tanks are designed to allow for expansion.

You can fuel from cold fuel (in the ground or on a cold night) then parked it in the noon sun or a warm garage. Spilled fuel is never good news or a good idea.

The neck gives you an air space on top for the expansion. I believe the neck also serves as a "Slush baffle" so fuel does not leak too much when you toss the bike around.

If you are patient you could fill all the way up by waiting for the air to burp out through that hole. The gain would be small. I think the norm is 3%.

If the hole is plugged then all the expansion will go up the neck (As there would be air around it) and the fuel would flow out the top.

DP

I'm not quite sure we are agreeing. The expansion is due to air expansion in the tank but not in the filler. It is also partially to do with fuel expansion but the air expands with a rise in temp faster and far more.

Without the breather hole, as the air above the gas expands it would push down on the gas forcing the gas to rise up into the filler tube and eventually running out the top. The filler cap is not sealed.

By putting the breather hole in the neck, the expanding air escapes from the trapped area above the gas, equalizes pressure in the filler tube and escapes out the gas cap without pushing the gas to overflow.

If the expansion was due to gas expansion, the breather hole would do little to stop gas overflow.

[Sandy]

Without the breather hole, as the air above the gas expands it would push down on the gas forcing the gas to rise up into the filler tube and eventually running out the top. The filler cap is not sealed.

It also allows you to squeeze another cup or so of fuel into the tank. Just make sure your going to ride away as soon as you're finished filling.

[posplayr]

It also allows you to squeeze another cup or so of fuel into the tank. Just make sure your going to ride away as soon as you're finished filling.

yea, but I dont press my luck that way any more.

Sandy,
Hope all is well with you and your family

Jim

[jwhelan65]

This may have just solved my problem....

http://www.thegsresources.com/_forum/showthread.php?t=168658

[posplayr]

This may have just solved my problem....


http://www.thegsresources.com/_forum...d.php?t=168658

Joe, this is a vent for when gas is filled up into the neck, once the gas is down to say 3/4 full it has no effect.

So this is not likely your problem, but it does sound like fuel starvation. I would pull the petcock apart and or change your filter. With a stock petcock on my 1166, kit I could roll-on strong for about 15-20 seconds before hitting fuel starvation with a stock petcock.