On Fri, 18 Jun 2010 19:09:32 -0400, Jim Elbrecht wrote:

there have been enough folks down this path before to make
it profitable for someone to carry replacements.g

My Craftsman 917.388853 6.5 HP 21" push mower (Consumer Reports Best Buy in
2005) came with this "fancy" gas cap that supposedly "preserved the gas".

After a couple of seasons, the fancy gas-preserving cap couldn't preserve
itself, and it broke into pieces. I just put a gas-can cap on. It fit. But
the engine kept quitting after a while. So I loosened it up when I was
cutting the lawn.

I'm curious WHAT is the difference between a gas-can cap and a lawn mower
gasoline tank cap? (The threads are the same.)