Boat ran great last week.1981 , 150hp Evinrude . Bump the key , it fires right up and runs smooth. Seems to smoke more than normal. Not enough power or speed to plane out. If I throttle up in neutral the engine only revs what seems to be about 1/3 of it's normal speed but if I tilt the engine to about 30 degrees it revs close to normal.My tach hasn't worked since I picked this boat up. I assume I have some sort of ignition problem.The plugs are new and good fuel onboard.I pulled the plugs when I got home and 5 appeared wet with one good clean plug.The engine runs smooth but slow speed.It really guzzled the gas.Would really appreciate some advice even if I decide to take it to the shop. Thanks !!