LOL, Yes, I think I have replaced the duckbill valve on all of my saws. The good thing is, most all the older Poulans use the same valve. Just some of them aren't in the cap. When ya order, buy several. They are cheap, and like I say, most all use them. They are a easy fix for an annoying problem.
Gregg,
Yep get at least a half dozen at once! There still used on alot of Elux equipment even today.