How many wires need to go tach

[199675hpforce]

Looking to tackle why tach is not working. New boat to me, use to have johnson motor then switched to 2000 yamaha 90hp 2stroke carby. Have no idea of wires or color codes under dash. Willing to have a look, yellow is 12v ignition key on,black is ground, green is send is this it?

 

[Reel Kahuna]

Re: How many wires need to go tach

That's correct.