Originally Posted by nhdoc

OK, I see now what the crush washers do, thanks. Looking at the photos in this wiki again helped refresh my memory:

http://www.peachparts.com/Wikka/OM606DeliveryValveSeals

My problem was I didn't see how the crush washer got centered over the plunger part when you screwed the DV cover on but it looks like it is tapered some to help. I wonder if some people who have terrible troubles after doing the job muck up the centering of the copper washer and that's what causes poor running since that might interfere with the operation of the plunger part?