Well here's a humorous one for you saw guys. Went to go finish bucking up that maple I felled and mentioned the chain amongst other general maintenance. Well in my haste I didn't tighten the bar cover nuts and sure enough the chain popped off. No big deal, so I try to reset the chain and it looked like some of the teeth that run on the sprocket were damaged and wont fit into the bar without force. The question is do I need a new chain? The chain won't spin even when the saw is running.
Clean it good with brake clean / soak in a little gas don't want filings in the bar grove. Check the drive sprocket/rim for damage.
Filed them down, 2 or 3 were in really bad shape. Set the chain and worked it back and forth and it worked fine.