Hey Thompson<br />Wires may already be there<br />You'll need switched 12V+ from ignition switch (purple I believe, may be red)<br />Ground (solid black)<br />Send signal (grey wire from rectifier)<br />Be sure tach is matched for # of poles/pulses on your motor (12 pole/ 6 pulse I believe)<br />Good luck
Thonpson, If that motor has a seperate belt driven generator and external voltage regulator, I do not think a standard Tach will work. I think those old motors needed a tach driven off the distributor. I would check the application charts for the tachs, and if no good, you may need to buy an OMC tach made especially for your motor.
If all wires are ok you should have a gray wire with the label "Tachometer" , if you are missing this wire you can just connect a new wire to the - pol on the coil .<br /><br />You might be able to connect it to the output from the stator BUT then you will need to find a tach handling 36 poles .<br /><br />Just stay with the std wire from the coil , then you can use ALL tachs handling 4 pulses pr rotation ( same as any V8 4-stroke engines )<br /><br />Using instruments from Teleflex on my 1964 90hp Johnson , WOT = 5000 rpm .<br />
.<br /><br />Just stay with the std wire from the coil , then you can use ALL tachs handling 4 pulses pr rotation ( same as any V8 4-stroke engines )<br /><br />Using instruments from Teleflex on my 1964 90hp Johnson 
