Tach ratio

[Hondell750]

Does the CBX tach have the drive to RPM ratio stamped on the back? My 750's do. I don't have any origonal CBX instruments to look at so I'm at a loss.

Thanks

[EMS]

No, they don't. What is your concern? Are you trying to use a different instrument?

[Hondell750]

Yes, my X was missing many parts: a basketcase really. I mounted a Fireblade instrument cluster and designed a pulser for the speedo and now one for the tach. "Most?" Hondas of that era were a 4 to 1 but I was hoping that it was marked. My bikes is in the corner surrounded by other projects and makes it hard to spin the engine and look at the tach drive to figure it out. Thanks for that info though.

[EMS]

The tach on the CBX is driven by the cam. I have no idea what ratio it is. Considering that Honda at a later date superseded the original CBX tach with the tach from "F" models, (like the CB900F and early CB1100R), I would assume that the drive ratio is the same on these bikes. But if you are working on an electronic instrument, what does the mechanical drive ratio of the original tach really matter? you are going to tap into the ignition system, aren't you?

[Hondell750]

No not the ignition. The fireblade cluster requires 2 pulses per rev. and a CBX is 3. I make small senders which screw into the drive and spin a pulser wheel. Thanks for the changeup info on the tachs. I'll look into that.