I have a 2007 merc 4.3 with raw water system. Last year (my first year of winterizing) I used Muffs to circulate antifreeze after first draining water from the 5 plugs. This year I want to take Dons advice and drain water then pour antifreeze in through the hoses. The steps I plan to follow are 1) remove the 5 drain plugs and remove water from system, 2) replace the 5 plugs, 3) open each of the 6 hoses near the thermostat housing, 4) pour antifreeze into each hose until the hose is filled, 5) reattach hoses to thermostat housing. So my question is: do I have to remove the thermostat housing to do this correctly? Do I remove the thermostat itself? I also plan on removing the outdrive and placing it in the basement, so water left in it is not a concern for me. Thanks in advance for any help with this.
