It's not an early Yoshimura pipe, but something based on one. Possibly modified for local sound requirements. I had an early Yosh pipe on my '75 Z1.
Definitely a Yoshimura pipe. That 316 is Graeme Crosbys number he used while racing with Yoshimura....I believe that is the bike he used at Daytona Yoshimura F1 here
Just to be clear, I wasn't saying it wasn't a Yoshimura pipe. I was making the point that it wasn't an early Yoshimura pipe. The ones like the one on my Z1 were available many years before the Yosh GS1000 were being raced.
^ I was at Brainerd International (BIR) and this young kid about 13 years old with a Southern accent , and a whole lotta confidence showed up, kicking ass and taking names. Yup, John Kosinski.
Early days of learning. Looks better than just duct tape to save your leathers. Might be a little ice racing rub off.
Cycle Tech showed up at a 6 hour endurance race at Loudon that same year. John wasn't the fastest guy out there, but for his first time there, at his age, it was pretty impressive.