boat seems held back and i smell exhaust?

What do you mean by heavy handed?

Is the cable heavy to handle or the throttle link on the carb itselve?

Replace the cable!

Sounds like the idle mix is set to ritch at idle.

Turn the idle screw complete in till it bottoms out, then back off 1.1/2 revolution.

Start the engine with the throttle cable removed from the carb-side.

Now first set the fast idle screw (throttle linkage stop screw) so that the engine keeps running @ idle.

Turn the idle screw until you reach the point of highest rpm or (highest vacuum) , re-set the fast idle and set engine rpm @ 750/800 rpm and repeat the above.

Good luck,

Frank

rich exhaust means too much gas, not enough air. Is there an air filter and has it been replaced? Is the inlet blocked?

I am not sure if the carb was rebuilt or replaced. A new carb may need adjustment, a rebuilt may have been rebuilt wrong. I don't know your carb, but a sticking or mis adjusted float/needle valve would run rich. you might also check the choke is open all the way.

Hope you got a manual with the new carb, it needs to be calibrated with the engine. ie the idle speed screw and rich/lean screw need to be adjusted.

Furthermore, are you using the correct oil to gas ratio for that engine?

i would check floats for sticking or check fuel/air mixtures