Winterizing 496 HO Mag
 

First time winterizing my new boat with twin 496 HO Mag's

Add 2 stroke oil and Lucas fuel injector cleaner to fuel filter and run?

Pump the air in the valves and done?

To be safe you will want to run a few gallons of pink through the muffs after purging the water. Not worth risking an heat exchanger, etc. over a few dollars in RV anti-freeze.

Mercury recommends a "cocktail" that should be pumped through the engine to fog and treat with stabilizer. You mix up a gallon and run the boat on the external gas can. While running on the "cocktail", run pink anti-freeze thru the muffs to fill the system. Also be sure to change your oil, outdrive gear lube and change the fuel filters when the fogging is complete.

Do a search on here. The Air Pump system is NOT for full winterization, and especially not at your latitude. There have been many posts about this.

The Air Pump system is designed to prolong your boating season, not replace a full winterization with antifreeze in the cooling system. The Air Pump system will leave pockets of water in your cooling system; especially in the fragile coolers.

+1 I used my air pump to empty the lines before replacing my impeller on my 496 last week. When I pulled the intake hose off and removed the sea water pump, I was surprised at how much water was still in the system. Wouldn't want to leave that in all winter!!

I've mixed a lot of cocktails, but what's my boat like?

....and approximately how many gallons of pink for this system?

I drain the water out of the system, and run 3 gallons through on just stabilized gas.
Then I add the 2-stroke oil to the fuel/water separate and run another 3 gallons through.

6 per engine if done that way.



If you drain the water, and mix up 2-stroke cocktail in a separate gas can for fogging the engine vs. the method you originally posted;
5 gallons of antifreeze would be minimum; and standard for any BBC.

The cool fuel system has to be drained by itself. Mercruiser school has been preaching this for the past 5 or 6 years. Not hear say because I attend them.

Gen III cool fuel back side hoses or the bolt that holds the hoses to backside of cooler needs to come off. If boat is on the trailer then jack the bow up high to drain fuel cooler completely after hose removal. Later years has the blue drain plug to pull out but that was not 100% full proof.

Early years Mercruiser 496 had the Gen II style cool fuel, make sure that gets drained as well because not knowing what year / serial # 496 you have to determine which set up is on your engine.

2005 and Engine Serial Numbers: OW008002 & OW008003