Newbie Tach question

[NICKINKZOO1]

I'm really new to outboard and have a question i need to get figured out fairly quickly. I have a 68 Mercury 500 no generator/manual start. I need to know if i can hook up a tach to this and if so what ones i need to be looking for. I am doing the body work on my 69 GW Invader hull and need to know if i need to fill the hole or what size to make it before i get to paint!!!!


Oh ya i should add,, there is no tach lead in my control box,,, there is the plug on the front but no wires going to it inside. So i need to get signal from the motor!!!
THanks a lot

THanks a lot
Nick

 

[Yepblaze]

Re: Newbie Tach question

I'm was going to punch in your info at

http://www.maxrules.com/MERCwireindex.html

and see if I can bring up a wiring diagram...........


But I see in that year range you provided there are at least a couple types of ignitions used and each one would derive it's tach signal in a different manner.

Perhaps you could look at them and figure out what type ignition you have on your motor.

But if this helps......


A old style stand alone magneto can use the kill wire as signal.

Most any motor using a stator under the flywheel can use the pulses from that to derive a tach signal.

And most any other type ignition would have a specific point on the ignition system that would provide signal.


That being said each different source might require a different setting on the tach, or tach itself.