I had my 021 in the shop for a new carb to be installed. Runs great now, but I noticed the chain tensioner screw was missing. Don't know if I lost it or the shop lost it. So I decided to order one. But after numerous clicks, numerous web sites that were difficult to use, I tried Amazon. The part came up on the first click and is to be delivered in two days. I try to avoid Amazon and Chinese parts but sometimes it is just so convenient.