Can I toss in another chain question?
Do you need a master link at all? I installed a new chain on my son's bike. It is a KMC 6-7 speed and came with a master link. I shortened the chain to the correct length, then used the chain tool to connect the chain, no master link used. Any problem with that?
Chain pins shouldn't be pushed out and then used to reconnect as it flattens the factory rivet (push pin out to shorten chain and then use same pin to reconnect). Is this what you did? It's best to use the included link.
To get technical, chains out of the box are classified as RO and PPO.
RO - Roller link Open - have 2 "open" inner links that must be connected with a master link (even if you cut the chain)
PPO - Pin Push Out - have a pin sticking out of one of the end links (outer link) that can be used to push in and connect the chain. The pin doesn't have a rivet or "ribs". This is only for lower speed chains.
Useful? maybe not. Let me know if I can clarify or add on.