This is to give general guidelines for the winterization of inboard engines that have internal, heat exchanger type cooling systems. Variations will become evident for different brands of engines; the principals will be the same. Engines do not freeze. It is the water within the engine and peripherals that freezes and causes damage. To preclude freeze damage you must either eliminate the water or make it so that it will not freeze.Good steps to follow:
1) Check the specific gravity of the internal coolant. Antifreeze checkers are widely available, and very cheap. Depending upon your location, be assured that the freeze protection is adequate. If protection is marginal, either drain some off and add 100% new or change the whole lot. Antifreeze should be changed every three to five years, according to Yanmar and the AF makers.
2) Shut off the sea water intake seacock, if the boat is in the water.
3) Take the hose off the seacock and put it into a jug of environmentally friendly antifreeze. It is sometimes easier to remove the hose at the pump and use a different hose into the jug.
4) Start the engine and run it until the antifreeze comes out the exhaust.
5) Reinstall the hose to the seacock.
6) Reopen the seacock after the boat is hauled. If the boat is to be left in the water, the seacock may require winterizing, again depending on the severity of your winter.
If you are not located where winterizing is required read this through and purr.
It is highly recommended that if the lube oil needs to be changed that it be done prior to lay-up so that fresh oil is coating the innards of the engine. If fuel filters are in the plan do them first. Then start the engine to check the fuel filters and warm the engine to facilitate the oil change.
Mail (will not be published) (required)