you can find it probably at the hardware store. just look for a one way check valve. it allows are in the tank, and no gas to come back out.
i have one here, send me a PM with your info and I'll mail it to you.
got one from kragen and it has been working good. it was in the isle, dont bother asking the people at kragen are clueless.
when/how did you lose your hood?
at the october freeride. it didnt come completly off, but both the hood latches broke and it shifted to the side about four inches and sank. the only thing that kept me from losing the hood was the hood straps. i switched to the EJ's bionic hoodlatch sytem.