So I installed my new chain and it was working fine for an hour. After that the chain started skipping on the 1st gear, but worked perfectly on the 2nd gear.

When I got home, I fiddled around with it for a while, turning screws almost randomly in an effort to solve the problem. I had reinstalled my old 8-speed chain which worked perfectly before, but by then I realized the chain would get stuck fast on the first gear.



The pic highlights the exact position the chain (on the outer cog) would be stuck such that I couldn't turn my crank at all. It takes a fair amount of effort to yank out the chain from between the chain tensioner and cog. Apparently the width between the chain tensioner and cog have been narrowed by my investigative tinkering.

My question is thus: What do I need to screw to widen the space between the chain tensioner and cogs? Thanks for any advice.