Gas overflow

[daveyb]

Has anybody had this happen?;
i filled up with gas the other night and when i kicked the bike over, it started right up and then proceeded to dump large amounts of gas out of the right tank through the cap. bike stalled. i cleaned it all up and kicked 'er again. started right up and i rode home. nobody i've talked to has ever heard of this. the only thing i can think of is maybe the cross-over got clogged for a minute, vented cap not venting? vapor lock? clogged filter? . has anyone been through this and found a cause? i would sure like it if this didn't happen again! kind of messy.

[fourthgear]

What was the temp. out side ? You can put cold gas in a warm tank and it can expand very quickly and blow out the cap relief valve. I have seen it happen when they pull the bike upright after starting.

[Cotten]

Beware also of reproduction gas caps that look like Eaton's, but vent deep within the cap instead of properly out upon the edge.

Modern fuels swell the rubber seals until they block the vents. Thus pressure in one tank can blow out the cap on the other.

(I lost a very expensive paint job to a pair of Tedd's caps because of this!)


....Cotten

[64duo]

Cotton,
can you post pictures of both repop & original caps to clarify that difference?
64duo

[panhead]

Eaton cap.jpg

[Cotten]

Thanks Mr. P!

The arrows point to the vents; On the left is an original Eaton (Trade mark in inset) with four creases that open below the gasket. On the right is one of the reproductions with vents above the gasket.

When the rubber gasket swells from a digestive fuel, it blocks the vents, allowing pressure to build. This is not only damaging to paint, it is a very real fire hazard.

My only solution is to trim the gasket after it has swollen.

...Cotten

[DuoDave]

I have repop gas caps on my bike, but the vents are like the original Eaton cap in the photo. My problem is that if I fill the tanks right up, I get gas dribbling out of the vents as I ride over bumps and the gas splashes up onto the inside of the cap. The solution is simple, don't put so much gas in the tank. It is irritating that I can't use the full capacity of the tanks though. Did this happen with the original Eaton caps?

[Skip]

DuoDave: Mine do the same thing...thought my tanks were leaking at the neck and had them lined, only to find out it is the damn caps...really pisses me off too, because I didn't notice until after I got my first "nice paint" job...sorry no help, misery loves company kind of thing......I do what you do...don't fill quite so full...Skip

[daveyb]

i don't think it was my cap. i found a lot of crud in the tank including large pieces of what may have been a wasp nest. these tanks were dirty when i got 'em and i spent quite a bit of time cleaning them, pressure testing, etc. obviously not enough! i think the bottom cross-over got blocked. i got the tanks off and now i'll clean them again, this time much more thoroughly.