I was told that a little bit of foodgrade lubricant dose the trick...it should be avaliable at your local brew supply store....i havent tried yet but it sounds feasible!! i had the same problem and those poppets are kinda expensive to replace...they are like 5:00 dollars a piece.
In your opinion how long should lager yeast starter let ferment before pitching? and what temp.? Is 67 deg F ok just to get it going.. I'm using a German Lager YeastWLP830...