Installing tach on a johnson 50 o/b

[H2Odog]

How do you install a tach on a 96 johnson 50hp 2 stroke? can you? and is it easy to do?<br />thanks<br />woody

 

[sonnie]

Re: Installing tach on a johnson 50 o/b

yes it is possible. i'm hoping that one of the experts will be able to give more detail, but from what i know from the older motors is;<br /><br />1) the tach wire is normally the grey wire in the harness. this wire comes from the rectifier which converts the Alternating Current from the stator to Direct Current.<br /><br />2) on the tach would be at least 3 terminals. one for + the other for - (12V) and the third for the "grey" wire ac (~).<br /><br />3) what i have not figured out yet is the calibration of the unit, although, if is the tach that was originally spec'ed then it should read correctly. (this is where the experts would be able to tell you.)<br /><br />it sounds like an interesting project and i hope that the above helps somewhat.<br /><br />sonnie

 

[H2Odog]

Re: Installing tach on a johnson 50 o/b

Thanks for the help. A couple questions though. You are right there is a grey wire from the rectifier, but it doesn't come directly from the stator, it ties into the vro pump and also to the boat harness. There is a yellow wire from the stator to the rectifier and also a yellow/grey one from stator to rectifier. There is no tach originally specified, so i am not sure what the calibration would be. <br />thanks