As the primary chain has been running very tight it is likely to be strained and stretched, and personally I would just fit a complete new Renold chain, and I think that it would be false economy not to. If the chain fails at any speed it can pile up into the front of the crankcase, jam the engine up solid, and even break the crankcase.
Renold 1/2″ x 1/4″, 69 pitches and connecting link.
Brian
