tach question

[Bigdaddy]

I had my boat repowered with a 1986 Yamaha 150 and the guy did not hook up my tach. Have a green and black wire out the back. He did a terrible job of wiring it up and is in jail so I dont have any recourse. Nothing in the wiring harness he put in to plug into. Where on the motor can I wire it to? Thanks in advance.

[boats.net]

The green wire and black wire on tach connects to green wire and black wire at control box(if it's a side mount control box) or the Ignition switch(if has ign switch in dash).