HT leaking petrol/fuel cap

[will_start]

So the new caps aren't perrfect, surprise, surprise.
Fetor said the vaccum effect took a month to catch up to him.
I was getting bogging from the rubber seal technique above,
and I was having to undo the cap every 20 mins or so to reset the pressure.

Today I drilled two small (like 0.5 mm) holes, one in each of the cap triangles.
No bogging in a 1 hour ride. More testing needed, but it feels so good.

 

[Knol]

Reinventing the "proper" vented cap?

Check any modern commercial Japanese or European "landscape industry" 2-cycle gas cap sometime. Doesn't leak when the machine is inverted: has a vent. Cap vent allows vapor to pass, doesn't allow liquid to pass. (Many other caps work this way as well, check a deep cycle lead acid battery if that's easier) Crappy gasoline (non-aviation) is sensitive to vacuum and will boil out (vapor lock) at surprisingly low temps if expected to live at much below atmospheric pressure. This is bad enough, but even without vapor issues expecting a gravity-fed fuel-lubricated engine to stay in one piece as the mixture goes from lean to "won't run" because you are progressively starving the poor thing for fuel/lubricant, even if it was accidentally on purpose is a good way to ruin your whole day. Just my 2 cents, again.

 

[Flapdoodle]

I discovered my cap was dripping gas from where the domed top was crimped on. Gas would slosh into the 4 holes in the bottom and the two rectangular holes for the latch, then work its way around the crimp.

Make sure the cap is clean.

I used Gorilla Glue once I had determined it seems gas proof and dribbled it into two of the 4 holes with the cap inverted. After a few minutes I set it on its side using a large pill bottle as sort of a stand. While watching TV I rotated it many times, a few minutes between rotations until I was sure the glue has set up enough. The next day I center punched the top and drilled a #60 hole for a vent.

No more leak and very little labor.


Glue is shown in red.

 

[5-7HEAVEN]

I have a locking gas cap for my Happy Time fuel tank.

No leaks either, and it vents through the keyhole.

Search the forum and you'll find it.

 

[bacon3787]

tank foam

To fix my leaking cap I bought some foam that goes in fuel tanks to keep fuel from sloshing and put it into the tank. now the fuel doesnt bounce up to the holes in the cap and leak out. The downside is you cant see how much fuel is in the tank.

 

[sparky]

That is a novel idea that I haven't heard about before.

I'm positive that will help somebody out, but I'd still prefer if the damm caps would just seal.

 

[will_start]

I bought some foam

What does the foam cost ?
I would love to stop the leaks...I hate smelling like petrol.

 

[kiwirider]

I am interested in the foam. Is there a web address you can give us to look at? Did the foam reduce the tank volume much? I do not use the HT tank, I have a tank from a 2hp Yamaha outboard. It is much smaller, 1.1l in total (.3 of a gallon) so I have to carry extra fuel.

 

[Skyliner70cc]

I have a locking gas cap for my Happy Time fuel tank.

No leaks either, and it vents through the keyhole.

Search the forum and you'll find it.

Can you just help us out and give us a part no. or a website that we can get one without having to waste precious time using this sites search function?

thanks!

 

[mowrrrman]

fector56,,,try a friendly bribe to the sales man to make up for his having to explain the opened packaging.. Often it opens doors and half the time they will refuse the bribe and still open the package for ya... For me I am just hoping my doubling up of the gasket stops the leaking... I just installed the extra gasket last night and while it seems to work when lying it almost on it's side I will not be sure it works till after It proves itself in today's ride... I do not care about losing the gas but I hate having to change clothes when I get indoors. Almost to it's high today of 33degree's here... This will be the warmest I have ridden my new build the "mighty mot0 mountain trek" newbie mowrrrman