82 KZ750-What are these supposed to sound like

pardon the potentially really stupid question but this is my first UJM and I honestly don't know. What are these things supposed to sound like? Is there a lot of mechanical noise? I've spec'd the valves with new shims and just tensioned the cam chain with a manual APE tensioner. Everything seems to be running fine but it kind of sounds like a sewing machine. Is this normal?

Be sure you don't have the cam chain too tight.
Steve

The 750/4s have a primary chain which will rattle quite a bit if the carbs are out of sync and a bit less if synced but they are still a noisey air cooled 4 cyclinder UJM and will never sound as quiet as a modern liquid cooled motor.

Mine has been rattling away happily for the past 16 years and 50,000 km.