Fuel cap issues

[kendunn]

Of all things to break first on my new to me 2002 EC300 was the gas cap. Cruising down a backroad on the way to a local trail and it started acting like it was running out of gas and died. Pulled the fuel line off the carb thinking my filter was stopped up or something and heard it start sucking air in. Hmmmmm, I thought, stopped up vent tube, but no. Took the fuel cap off and the rubber was collapsed on the bottom of the cap. Blew on the top of the cap and it popped back open only to close up again about an hour into the ride. Is this a common problem or is it just my good luck? I figured I could just cut a bigger vent hole in the rubber or something. Will this solve the problem?
Thanks
Kenny

[wence]

From what I have heard it will but my rubber boot actually came away from the cap therefore not sealing at all. I think even over here in Oz the cap only cost $15- $20.
Cheers Mark

[kendunn]

Originally Posted by wence

From what I have heard it will but my rubber boot actually came away from the cap therefore not sealing at all. I think even over here in Oz the cap only cost $15- $20.
Cheers Mark

I don't mind to buy a new cap, unless its a widespread problem that keeps repeating itself and there is an easy fix like cutting a bigger hole . Thanks for the input, I figured someone else had this problem too.

[GMP]

kendunn,

This problem does happen from time to time, and as I see it it relates to various fuels and their effect on swelling the rubber cap gasket. It has happend to me in an enduro, and also Fred Hoess when he was on GG talking to his mech. Remove the rubber gasket, and enlarge the pin holes or punch the center out completely. Now remove the plastic part with the three vent holes that retains the ball bearing check valve. Enlarge these slightly as well. Reassemble and all should be good. If the rubber gasket is swollen to the point of being distorted, replace the cap, but modify before use.

[gasser]

Do gas caps really need all those extra parts? Are they just to keep gas from spilling out during a tip over?

[GMP]

Its simply a check valve to prevent spillover. If you use an external check valve/vent cap you can remove the ball in the cap, but some of these tend to be of poor quality and stick. I just have a plain shorty vent hose cap and retain the ball bearing in the gascap.

[reiterrider]

Just buy one of these at your local mx store, they are less than $20. Problem solved.