I just got a used 15hp '83 Evinrude and have been trying to get it usable. I know a little about engines, but I'm no mechanic, although I do have a manual for the motor type.
I have replaced the spark plugs and fuel pump, replaced the gear oil, and taken off and cleaned the carborator with (spray can) carborator cleaner. It starts, but smokes a LOT, and dies after about a minute, no matter what speed it's running at.
Welcome to Iboats!
When it starts to die try squeezing the fuel primer bulb.
You may have a fuel line sucking air or carb problems.
Did you remove the core plugs inside the carb and clean all the orifices?
Usually just spraying carb cleaner through them does very little.
Pump the primer ball up and look for any leaks.
1981 ChrisCraft 210 Scorpion K,175 Johnson SeaHorse
The only way to clean a carb is removal and total disassembly,It is probably smoking alot because it was "pickled with oil"before laying uphowever 2 cycle engines do smoke because oil is mixed with gas