The only time I lost one was filling up one night and left the cap on the gas pump, or at least that's what I figured happened. I didn't notice it until a few days later when I opened up my fuel door to get gas. I now put the cap on my seat when I take it off.

Have you tried cleaning the cap and/or replacing the seals? That may fix your problem. Or just buy new caps. I'm sure that would be money well spent and they should last for years. A small investment for a lot of peace of mind. Just one more thing ya ain't gotta worry about.

 

Yea, I screwed it up. The gas station is exactly one mile from my house. I filled up, rode home, it was hot out.. Get up the next day and there are nasty streaks on my gas tank. I worked and worked on those and never could get them to go away. Over time they have faded on their own. Anyway, sometimes I'm slow to learn.

In the summer, after a ride, my gas tank will hiss for a while. I suspect it's doing as it was designed to do.

 

I don't think that what's happening to your bike is "normal". Just think if this was a new bike. Would you accept gas venting and leaking all over your tank as "normal"? I think either your cap's vent is not working correctly, your cap seal is bad and/or your cap is not fitting correctly. My tank will build up pressure, but it never vents out of the cap. I've just never experience enough pressure for it to do that. Maybe someone else knows something else or has a difference opinion or experience. If so, please share.

 

Just been through this with my 1999 Heritage found the one way check valve that mounts on the back of the rear pivot bolt was stuck, pulled it off blew through it with compressed air which freed it up. The fuel cap on the Heritage only let's the air in and the other valve vents when the tank builds up pressure this valve connects to the right hand tank with a hose tht runs down under trim, then next to the battery, then down to the valve then to the bottom of swing arm assembly where shocks mount. When I say went through this had four or five litres of fuel pour out of the pipes of the bike, pressure built up that much that over pressured the vacuum diaphragm in the pet **** and the needle and seat in carb was just lucky someone I knew walked past and called me. Took a couple of hours to work out the issue, but still don't trust it 100% since on a hot day I turn off the fuel to be sure that it does not happen again

 

DANG! I was wondering what that thing was for when I mounted my air compressor for my air horn....THANKS!