I ALWAYS store my engines with oil in them. I thoroughly clean the carb, put a cap full of oil in the top of the cylinder and rotate the crank a few times. Come spring it gets a new fuel pump, filters and fuel lines whether it needs it or not.
Run the engine up to operating temperature and change the oil. Put in fresh 4T oil.
Remove the spark plug and squirt a small amount of oil in the cylinder.
Turn the engine over a few times to distribute the oil around the cylinder.
Put your thumb OVER (NOT IN) the spark plug hole and turn the engine over to get the piston at Top Dead Center on the compression stroke.
Replace the spark plug.
This is also a good time to check or adjust the valve clearance.
Remove large brass plug from the bottom of the float bowl and drain the gas.
Remove the fuel line and drain gas from fuel line.
Squirt some WD 40 into the fuel inlet nipple of the carb and let it drain out.
Cap the fuel inlet nipple of the carb and replace the brass plug in the bottom of the carb.
Remove the air filter and seal the carb
Remove the breather hose from the valve cover and seal the hole
Seal the muffler.
Store the engine in a warm low humidity environment.
This is also a good time to perform your clutch maintenance.