Magnum gas cap leak...help!

No matter what I do to the gasket inside the gas cap, I still get a leak right around the seal...I doubt it's coming from the base of the rim, but more like the top. I've tried moving the gasket down more and up, but nothing works. Anyone know what I should do? The tank was kreemed, and some is on the back end of the cap, but I don't think that's effecting it...

Any solutions? Holding a rag every time I ride is beginning to be a real pain in the butt...

Re: Magnum gas cap leak...help!

See Ya Moped Army /

<some is on the back end of the cap>

Sounds like you may have clogged up the breather hole in the cap. Make sure the breather hole is clear by running a piece of wire through it.

Re: Magnum gas cap leak...help!

Thanks mopedlar...I tried cleaning out the breather hole and removed some kreeme that stuck to the gasket/some other random parts on the cap.

I don't know if this was the case prior to me poking around, but I can rattle the thing like a baby rattle. I tapped it on its side and bits of rust fall out...is this going to be a problem when I ride?

I do have the inline fuel filter, but I'd hate to replace that constantly because of a rusty cap...

Re: Magnum gas cap leak...help!

i think you have the wrong cap there.. or the gasket is shrunk and no longer seals.. Try cutting another gasket from a piece of rubber sheet and adding it to the gasket.

And it shouldn't rattle .. There is a little internal cap inside my gascap that is held in only by pressure.. a press-fit.. So my guess is your cap is falling apart inside due to being rusty and maybe banged around.

I pryed open a cap that was on a Kreemed tank.. the inside of the cap was packed with flakes of rust. The inside of a metal gas cap is a nearly perfect environment for rust development.

The inline filter might catch rust particles but it will not cure a clogged gas cap-vent. The tank has to be vented. Once you cure the leaking fuel/gasket/problem, the cap's tiny vent hole is all you will have..

imo, you need a new cap. Once you find one, break that one open and then tell me i was all wrong. :)

Re: Magnum gas cap leak...help!

Oh, I figured it shouldn't rattle...basically, until I get a new cap, will the old one be a problem? The rust falling worries me...

Re: Magnum gas cap leak...help!

A little bit of rust falling is no big deal. Screens and filters take care of that.

Assuming it's rusty inside, the rust inside the cap _can't_ get out. And thats the problem because rust clogs the cap's vent. Air has to be allowed into the tank to replace gasoline or fuel flow will stop.

i had an annoying performance problem.. like the bike was running out of fuel.. All of a sudden it would slow down for a moment and then, just as suddenly, everything was OK.. this went on for a week.

i traced the problem to the gas cap.. Understand that i had already very carefully cleaned the cap, run acetone through it and poked wire in the vent holes and blown it out with compressed air and all that.. What i didnt know was that the cap vent kept getting clogged up due to the internal rust.

The clogged vent produced a vacuum in the tank and fuel flow slowed to a trickle.

After opening and sandblasting the inside of my cap, the bike never had that problem again. Fuel now flows from the tank's hose in a steady thick stream.

btw, for a rubber gasket add-on as suggested in the previous message, use a piece of tire inner tube.. maybe two.. Whatever it takes to get a snug fit.

Re: Magnum gas cap leak...help!

Cool - Thanks for the help...that fuel issue happens to me from time to time too...almost makes the bike feel like a 2-speed with a shift lol

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