Installing a tach on a 15 hp yamaha 2 stroke

What is the best tach and easiest set up for a rope start 15 hp yamaha 2 stroke ?

I put a tiny tach on my 25 Yamaha, just wrap one lead around a plug wire and ground the other. Got mine for about $60.

I put a tiny tach on my 25 Yamaha, just wrap one lead around a plug wire and ground the other. Got mine for about $60.