Honda-SOHC

Other Stuff => Misc / Open => Topic started by: AshimotoK0 on July 20, 2014, 10:28:45 AM

Title: Speedo/tach Ratios on Honda's
Post by: AshimotoK0 on July 20, 2014, 10:28:45 AM

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

Title: Re: Speedo/tach Ratios on Honda's
Post by: SteveD CB500K0 on July 20, 2014, 01:11:06 PM

From sohc4.net:


CB750 Speedo  2240:60  Tach 4:1
CB650 Speedo  2240:60  Tach 4:1
CB550 Speedo  2240:60  Tach 20:3
CB500 Speedo  2240:60  Tach 20:3
CB400 Speedo  2240:60  Tach 20:3
CB350 Speedo  2240:60  Tach 20:3