problem with chain getting caught in engine idk why

my chain us going off the sprocket inside the engine and getting caught up in the top corrner, at first I though is was the master links fault from a chain I bought at the bike shop but I was wrong. New engine and new chain and this is happening and idk what to do.

I notased my tensioner was slightly out of alignment, corrected that and have been unable to stick the chain. So I THINK I probably sorted out that issue.

I think the longer cruiser frame with the longer chain necessary is less forgiving of alignment issues than say an old mountain bike, although when they are working they ride pretty nice