Your motor has CD ignition so that wont be causing the problem but something wrong in the carb is.
Did you use the proper OMC/BRP 439071 carb kit when you rebuilt the carb? It would have contained all of the necessary parts, including the welch plug, # 10, to totally disassemble and allow a thorough cleaning of the carb.
The main jet orifice, # 27, lies at the bottom of the bowl and is prone for dirt and corrosion plugging it up. All of the fuel used passes thru it so its condition is critical. The fuel passage coming from it up the side of the bowl and going to the low speed circuit can get plugged to causing idling symptoms similar to yours. Another problem area can be the condition of the low speed needle packing washers, # 16. If they are damaged, the motor wont run right as air will leak past them. If the nozzle gasket is missing, # 21, the motor would tend to run rich but yours seems to be running lean.
It’s time to go back inside the carb to double check the work you did on it. When the welch plug is removed, you will see a tiny hole which the point of the needle goes into. If this hole is plugged, guess what? No idle or poor low speed running. The carb must be blown out with compressed air after soaking to make sure all passages are clear and clean. While you are in there, recheck the float height and once the carb is back on the motor, check the synch setting between the carb and the mag.
Starting the motor with the needle about 1 1/2 turns out from lightly seated will allow it to start and it can be adjusted finer as the motor warms up. Always leave the needle a bit on the rich side from its optimum setting as this will give good throttle response and extra oiling for the motor.
