Fitting smiths tach to 83 merc 50

[Nos4r2]

I've got a Smiths 2-stroke tach and I want to fit it to my 83ish non distributor 4 cyl merc 50 blueband.According to my Seloc manual it's a type V ignition.<br />Have I still got to conect it to a yellow wire from the rectifier or does it attach to a coil feed or the switchbox?<br />It's got various settings on it-2,3,4,6,8cyl.<br />Which one do I use if I have to connect it to the rectifier? I assume that it's got to be set to 4cyl if it's attached to a coil feed?

 

[Laddies]

Re: Fitting smiths tach to 83 merc 50

If you hook to the ign it will burn the tach up and it don't sound like that tach is for an AC 12 pole alternator set up--Bob

 

[Nos4r2]

Re: Fitting smiths tach to 83 merc 50

Even if I hook it to a green wire from the switchbox?

 

[Laddies]

Re: Fitting smiths tach to 83 merc 50

I don't think a standard tach will stand the 200 volts input from the CD ign.

 

[Nos4r2]

Re: Fitting smiths tach to 83 merc 50

Ah. Didn't realise it was that high.<br /><br />Would it affect the ignition if I were to put a resistor inline from that 200v feed to drop it down to a voltage the tach can handle?

 

[Laddies]

Re: Fitting smiths tach to 83 merc 50

Don't really have a clue but I doubt it--Bob

 

[Nos4r2]

Re: Fitting smiths tach to 83 merc 50

Cheers Bob, much appreciated.