fuel cap

DevonCbx · Post by **DevonCbx** » Tue Jun 24, 2008 9:29 pm

Regarding my question earlier about the bike sputtering, I had spoke to a gentlemen about this problem and he said with his new bike he had some sputtering issues until he replaced the gas cap. It was not breathing properly. Is this a possible problem with my cap? Could this cause sputtering? Can someone please explain the theory on why a cap needs to breath to allow air in the tank.

Thanks

CBXRoger · Post by **CBXRoger** » Wed Jun 25, 2008 2:30 am

The air inlet is in the cap for the gas tank. Without air replacing the gas, the gas will cease to flow as a vacuum is created in the tank.

FowVay · Post by **FowVay** » Wed Jun 25, 2008 8:50 am

Off-topic but kind of related: I once replaced the cap on my lawn mower with a cheapy generic from Home Depot. I had no idea that those three tiny holes in that cheesy cap were actually a metered orifice for regulated aspiration. I bought a cap that had only one hole in the center.

My mower would start but would sputter after 30 seconds of operation. I could remove the cap and it would run fine. I ended up using a awl to enlarge the hole in the cap and alleviate the stutter.

So if liquid is going out, air has to go in. Remove enough liquid without replacing it with something and the container will crush under atmospheric pressure (14.7 PSI at the beach).

EMS · Post by **EMS** » Wed Jun 25, 2008 9:26 am

FowVay wrote:
So if liquid is going out, air has to go in. .

Funny that a statement like this needs to be made....Hasn't EVERYBODY on this site, at least once, had beer out of a bottle