I'm new to this sight but there seems to be a lot of really good info here. My question is I have a 1984 Yamaha 40 outboard idels fine has good compression on all 3 cyls. throws a nice spark runs good at low end of throttle. But has a reall loss or rpm's at WOT will not even get close to plane. Now if you hold the choke on the engine out 1/2 way it will run much better and almost get to plane. Tried squeseing the primer ball but did not help. Anyone had any similar prolbems with the Yamaha engines? 