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Cam to crank ratio

Posted: Thu Mar 29, 2012 12:06 pm
by Hondell750
I've fitted a Fireblade instrument cluster to my '79 and am coverting all the mechanical sending units to digital . Anyone know how many revs of the tach drive correspond to the crank revs? I'd do it myself but the bike is in storage as i'm in the middle of a move.

:text-thankyouyellow:

Re: Cam to crank ratio

Posted: Thu Mar 29, 2012 12:53 pm
by EMS
Not really the answer to your question, but the easiest way to drive an electronic tach is to tap into the ignition circuit. Don't know how the Frieblade tach receives its signal, but most modern tachs use the coil control wires to determine rpm.

Re: Cam to crank ratio

Posted: Thu Mar 29, 2012 1:05 pm
by Hondell750
Yes -true but the Fireblade uses 2 pulses per rev and the CBX 3. I can go into the trigger unit and shoehorn my electronics in there but I'd rather just bolt my sender onto the tach drive.