I was just saying that it was because I found a receipt where I bought one on eBay about 8 years ago. I don't think I've bought any other gas engines, so either it's 1) the Ryobi .31 that I bought then, 2) a smaller one, like dave says, and the seller ripped me, or 3) I bought a .31 and have absolutely forgotten it, and it's still around in the madness that is my attic.

Thanks, guys! Anybody care to give me an opinio as to what I should be asking for this bad boy when I sell it?