Winterizing a Yanmar 1GM10

On the Yanmar 1GM10 there is one block drain. Looking at the front of the engine to the back, the drain is located on the left side under the exhaust elbow. Open the drain and drain water from that location. Put the drain plug back in. Take off the water intake line at the thru hull and put the intake line in approximately 2 gallons of non-toxic antifreeze. Start the engine and run it until the antifreeze in the container is almost all gone. Go back to the block drain and open it to ensure antifreeze is there. If there isn't, continue with the above process with more antifreeze. Once you have lots of antifreeze at the drain it should be through the system and have gone out the exhaust. we drain the antifreeze out of the system from the drain and leave it empty for the winter. Reattach the water intake line.