Tachometer - Hooking up a Yamaha 7k Tach to a 1971 Evinrude

[Zabbu]

I'm trying to tune my 1971 Evinrude Lark and i'm unable to because the Tachometer that came with this old boat isnt even hooked up. From reading other threads I know that the tachometer cable will be grey and 'wrapped up' inside the remote control. I also read that i should hook the power up to the same power cable leading to my overheat horn / alarm as this has power while the key is turned on. However, i cannot figure out how in the heck this would coincide with the tachometer i have,

Below is a picture of the back of the Tachometer. Click on it for a larger picture.



I drew a picture in paint of the exact wiring. I used the same colors that are currently in place. at the end of the day i have a yellow, green, and black wire heading to the back of the boat. But the yellow seems to be going to a fuse then to the light? And the power seems to be set from "B" with a bar to 6? shouldn't I change that to 12 for 12v? And I believe the section labeled "G" is ground... and it is green.... but then that leaves me with what seems to be 2 power wires and 1 ground at the end of the day.



Could someone help me 'rewire' this to hook up to my 1971 Evinrude.

 

[Zabbu]

Re: Tachometer - Hooking up a Yamaha 7k Tach to a 1971 Evinrude

I am still confused by this tachometer. I showed my neighbor who's a bit more versed in this kind of thing and he to was confused.

 

[boobie]

Re: Tachometer - Hooking up a Yamaha 7k Tach to a 1971 Evinrude

Try hooking your gray tach wire to the 6 p position and see what happens. I don't understand Yamaha's wiring codes as they are different form BRP and Merc.

 

[Zabbu]

Re: Tachometer - Hooking up a Yamaha 7k Tach to a 1971 Evinrude

I stumbled upon a chart in another thread..

• Heres what i think i'm going to try,
• cut off both the wires that go nowhere.
• Go from the yellow/blue wire that meets the lights to my purple wire that goes into my overheat alarm/horn.
• Go from black to ground
• Change the bar from B to 6, and move it from B to 12 (assuming i'm then changing the tach to accept 12v
• then i'm going to take that green wire and put it to my grey wire.

according to the chart below this should work? Any thoughts on that? I'm trying to find a place that lists if i do have 12v coming from purple.

 

[Zabbu]

Re: Tachometer - Hooking up a Yamaha 7k Tach to a 1971 Evinrude

This did not work

I'm out of ideas on this on

 

[boobie]

Re: Tachometer - Hooking up a Yamaha 7k Tach to a 1971 Evinrude

Maybe you should get a tach that's made for the mtr. By the way, what's the model # on this mtr??

 

[Zabbu]

Re: Tachometer - Hooking up a Yamaha 7k Tach to a 1971 Evinrude

This did not work

I'm out of ideas on this on

1971 Evinrude Lark 50hp
Model 50172 or 50173, their basically the same.

I'm just trying to hook this one up since its the one i have in hand and what 'came with' this old boat i'm fixing up.

 

[boobie]

Re: Tachometer - Hooking up a Yamaha 7k Tach to a 1971 Evinrude

Bit the bullet and get the proper tach for it before you blow something in your charging system on the mtr.