Return to the leaking gas cap

[bobhamlin]

About a month ago, I wrote of a problem with a leaking gas cap. When I filled it to the bottom of the splash guard, I had a leak for about 10-15 miles-- gas would seep from the cap. Per some suggestions, the problem seemed to be a missing O-ring ("Oil seal," according to Kaw microfiche). I ordered one, installed it and, because I kept filling the tank in the dark and riding, I couldn't verify that the problem was solved--even though I thought I smelled gas.

Today, I filled it in daylight and the leak is still there. The seal didn't solve the problem. The O-rings for the cap hinge are in place. Several others here said they had no O-ring from the factory, several just never fill the tank to the splash guard.

I think I should be able to fill the tank, but what's the problem? BlownDodge solved it by removing a plastic diaphragm. Garry responded that the diaphragm prevented gas from spilling if the bike tipped.

My tendency now is toward BD's solution. However, I don't understand what is actually happening. We have drain and breather tubes (could something be clogged, or pinched?), one of which is supposed to get rid of gas safely beneath the bike.

To me, this is a serious design flaw. Kaw has to know about it. And once they know, they should be taking some type of action-- or the first time some of the gas ignites, it could be a gruesome court case.

[cactusjack]

I routinely fill my tank 1/2" above the bottom of the filler tube. I have never had a problem with gas leaking, even when it's above 110 degrees and my black fuel tank is hot enough to cook a burger on. I wish I had an answer for you.

[dogdoc]

I rountinely fill my gas to just slightly below the flange and I have no problems. the manuel says dont fill above the flange.

[Yellow Jacket]

I can only think of a couple of things to check.

Check that the overflow drain is open. That's the opening seen right underneath the yellow arrow in the picture. Try holding a piece of tubing against the opening and see if you can blow through it.

Also, check the cap gasket and it's mating surface on the filler opening. That's the big one that seals the cap against the filler tube opening. Make sure there are no nicks or dents in the gasket or the mating surface.

Check to see if the top of the filler tube is actually flat. Use something that you know is flat and is small enough to lay on the filler tube, like a small piece of glass or a metal block.

[blowndodge]

Nobody listens to BD anymore!!!! ::)

I told you I knew EXACTLY why your tank is leaking and nooooooooooooooooo.........gotta go buy something else insteadddddddddddddddddddddd......

When ya guys gonna learn!!!!!!!!! Amid all my sarcasm when I tell ya I KNOW the answer to your question you should stand around me like a burning bush!!!! ::)

In Bob's picture your going to have to remove the gas cap completely(those two brass colored philips head screws.

Now take the cap to a well lit table and remove the two (Bob's pic again) other smaller brass looking screws and take that plate off.

Underneath it all you'd find two black plastic half moon shaped pieces that are separated by a small spring. Each of those half moon pieces has a small hole and one of the pieces has its hole coved by a 1/8" diameter opaque piece of plastic. This is an emission thing that unfortunate wasn't machined well. When pressure builds in the tank that pressure is suppose to overcome the spring and let the fumes vent to the canister(not all Nomads have a canister but all have this cap!)

There are a bunch of little screws and pieces under That cap but after slowly taking it apart you'll understand how the lock works as well! It took me about 20 minutes of freekin with it until I put it back together. some of the pieces like the locking mechanism needs to be held together while you put it back on top. A little tricky but doable. I did it without too much cussin'

Next time

listen to BD.

[Top Cat]

I listened to burning bush, err I mean BD!
Back when i first came on here my tank cap was leaking a little and whistling alot. BD said to do exactly what he just told you.
I took the cap apart and removed the little wafer thing and put it back together.
No more whistle and no mare leak.
I fill my bike with it on the sidestand and fill to the bottom of the of the filler tube.

[blowndodge]

Blessed are those who have seen and believe. TC Go forth and deliver thy Nomad riders from the evils of bondage....!! Thou shalt not have no other BD before me!!

[audiogooroo]

Do you know the difference between BD and God?

God knows He's not BD! :)

[bobhamlin]

Originally Posted by Blowndodge "Darksider"

Nobody listens to BD anymore!!!! ::)

I told you I knew EXACTLY why your tank is leaking and nooooooooooooooooo.........gotta go buy something else insteadddddddddddddddddddddd......

<snipped>

Next time

listen to BD.

BD- I meant no disrespect. Pls understand my dilemma. I'm fairly new on this board and am one of those skeptical individuals that wants to make sure that, for example, a frontal lobotomy is the best treatment - rather than, say, cutting down on caffeine.

Another example, if I came here asking for help with a birth control situation, your solution would be in the "lop 'em off" realm. Granted, that would be a 100% solution, but I would tend to want a second opinion.

Again, no disrespect intended. With my relative newbie-anism, how would I really know that behind that sig photo of the chiseled, Schwarzenegger-ish physique and Eastwoodian masculinity isn't actually a 14-year old, pimply geek creating these posts from the computer in his mom's basement while attired in the accurate-to-the-thread Jedi outfit?

btw, I found a post on Gadget's site that explains how to lessen the tension of the spring that is holding down the diaphragm-- cutting a little bit of the spring.

[rewindgy]

Okay God, when I had my problem I tried your fix first and it didn't solve anything - sorry! It couldn't fix the problem because the seal was missing and the expelled fuel was not going out the overflow tube - just onto the tank and down my leg! After putting the seal back in I haved tried both stock and your fix on the cap and it don't overflow with either. It does on occasion whistle when very hot outside.

[blowndodge]

Bob, no disrespect taken my brother. It's just my style!

Rewindgy, if your cap is still whistling then you DIDN'T do what I recommended. That small piece of plastic that covers the hole is the source of the whistle. It CAN'T whistle with that piece taken away. FYI.

Bob, the reason some of us have this problem is that those two small plastic pieces are supposed to slide against each other. Thats only if they are machined correctly! mine would stick and the pressure in the tank couldn't overcome the stuck spring so it would force the gas out of the rubber gasket sealing the mouth of the gas tank all over my leg.


So it is written, so it shall be done....

[Top Cat]

rewindgy, again, I have to agree with the guy behind the curtain, there is no way the cap can still whistle if you removed the plastic wafer thing.
Bob, do what you want but it is much easier to remove the wafer than it is to try and cut the spring to the right size. ;)

[blowndodge]

Cutting that spring is for the birds. I wanted my tank to vent properly!!! no wafer!!

Audio: God still loves BD!

[rewindgy]

Ussus guys weren't listening. After the new seal I tried it first with the cap stock ( not modified BD style) no leaks but slight whistle when very hot and then cap ( modified BD style) no leaks and no whistle! Most important - no leaks on tank or lap!

[blowndodge]

We're getting old rewindgy..... SWB's noticed that he's leaking more on his lap than last year!!!