I dropped out the tank in my 71 Elky.After I took out the sending unit I tried to drain what's left of the gas.It's then I noticed something rolling around in the tank. I was able to get it out. It's a round piece of metal, one and quarter inches diameter, and has what looks to be a spring loaded diaphram in it.It's not much of a description, but does anyone know what this is? Thanks

Picture?

Probably one of them "get 10 more MPG" things.


LK

How about a picture?

detonator?

I remember that during the first gas crisis in the '70's many anti-siphoning/anti-theft contraptions were sold since dirtbags were resorting to stealing gas from everyone elses' tanks. I recall installing a cone-shaped spring into the filler neck of the tank on my Nova that allowed the gas to go in but kept anyone from inserting a hose of any sort into the tank. Perhaps the item you found is something along those lines.

Another possibility: I don't recall what year using unleaded fuel ONLY became manditory, but when that happened the opening to the tank had a smaller hole that only accepted the smaller snout found on unleaded pumps while the leaded fuel pumps had a larger spout which would not fit in these newer smaller openings thus forcing you to only ever fuel up with unleaded. Folks found, however, that you could knock this little flapper door out of the way with a large screwdriver and a hammer which would allow you to put (cheaper) leaded fuel in your car.

http://img122.imageshack.us/img122/466/gastankdebri2kg4.jpg

The vent part of a vented gas cap maybe?

Dave