The way to winterize any Sterndrive engine is the same. Start by running the motor on a hose to get the engine warm(15 to 25 minutes at idle). Shut the motor off and use a oil change system to suck the oil out of the oil pan (this is done at the fill tube). Change the oil filter at this time also. It is recommended that the lower unit be removed yearly to inspect the gimble bearing and bellows and to grease the drive shaft. I also check engine alignment while the drive is off. Install the lower unit back on the gimble housing and grease the gimble bearing (there should be 1 or 2 zerts on the gimble ring.). Refill the engine oil. There are 2 ways to get antifreeze into the engine. I prefer to use RV antifreeze and put about 2 1/2 gallons in a jug that I can hook my ears up to (the jug will need a shut off valve) . Remove the flame gimble from the top of the carb and have a can of are-sol fogging oil ready. I put the jug on the back of the boat and start the engine with the ears hooked up to water pickup on the lower unit. Reach back and turn the antifreeze jug on as soon as you get the engine running. It is nice to have a person on the outside of the boat to look for the antifreeze coming out of the exhaust on the lower unit (Once you see this the antifreeze has been sucked through the entire cooling system.). With the engine still running spray fogging oil into the carburetor and choke the motor until it stall and shuts off. You need to kill the motor before the jug is empty but after you see antifreeze coming out of the exhaust. Spay corrosion guard over the motor (hoses, block, manifolds, etc). You will need to drain the lower unit oil also. To do this remove the bottom plug on the lower unit and then the top. Make sure you have both of the plug seals. Fill the lower unit from the bottom plug until you have oil coming out of the top plug and install top plug. You will also have a gimble for gear oil mounted on the engine in a clear plastic housing. You need to slowly add more oil from the bottom of the lower unit until this gimble is at the full mark.
The other way is to add antifreeze is to remove the the drain plugs from the engine block and exhaust manifolds to remove the water from the system. Install the plugs back in and remove a hose or fitting from the highest point of the cooling system and add antifreeze until it is full (no guarantee that the system will be fully protected this way though)
The other way is to add antifreeze is to remove the the drain plugs from the engine block and exhaust manifolds to remove the water from the system. Install the plugs back in and remove a hose or fitting from the highest point of the cooling system and add antifreeze until it is full (no guarantee that the system will be fully protected this way though)