Anyone know what the ratios should be on CB750 and CB250k / 400/4 instruments of spindle speed to indicated MPH/RPM. I have got lots of sets of mainly CB250K0 clocks and I want to check them out by running them at various RPM's to make sure they are working correctly. I am using a servomotor from one of my 'work' projects with a calibrated tachometer on it to check them out, fitted with a square drive to suit Honda instruments.
My 69' 750K0 plastic bodied speedometer has this stamped on it (see pic attached)
Cheers ... AshD