525efi
 

Could anybody tell me what I have to do to winterize this motor? Not sure on this closed cooling heat exchanger. Thanks

All Merc says you have to do is use the bike pump on the engine and fill your heat exchanger up with air until the green "tit" pops out (you will hear water running to the bilge). Pump it up anytime to see what it looks like but remember to pull the ring next to it BEFORE you start the engine next time to evacuate the vacuum (important!).

In reality if you want to truly preserve your engine and components you should flush the engine with anitfreeze just like a regular engine. That will ensure that you have zero water that is unprotected for your Michigan winter. I would also change all the oils in the engine and sterndrive to be sure you have fresh, non acid laced oil to protect your investment.

Hope this helps, good luck!

Thanks from the information.