Very common chain issue, tight and loose, but has nothing to do with your clutch binding, most likely you have a slightly bent axle or a bad carrier.
It is very important you reply to Bryan Williams about the type of clutch you have though. He has a lot of knowledge, plus he has lots of engines, clutches and a bunch of stuff, if you ever need anything Briggs related, he is the man.
Is this your old engine, that you had no idea how many hours it had on it? Plus leaking oil at the cases? He has brand new ones in stock, and will be at Button willow this Sunday. Just sayin’