1986 Mercruiser 140 winterizing 1st time

CardiacKid74

Recruit
Joined
Jul 10, 2018
Messages
5
I'm winterizing my boat for the 1st time. I changed the oil and filter. Ran it for a good half hour to run antifreeze through it with a 5 gallon jug and T-fitting to shut off hose water and turn onantifreeze. I'm not sure it got hot enough to turn on the thermostat and get antifreeze to the manifold side. Any way I can check? I also fogged the engine until stalled once i got close to running all 5 gallons through.
 

Who me?

Cadet
Joined
Aug 28, 2008
Messages
16
Nah thats gunna bust ya block ya needs to drain all the water out or it and then add ya AF
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
Messages
51,399
You have to drain the block, manifolds and hoses to be winterized.

Attempting to suck up antifreeze simply pumps the anti freeze out the exhaust and does not get any in the block. So you will have a busted block unless you drain
 

poconojoe

Lieutenant Commander
Joined
Sep 10, 2010
Messages
1,966
As stated... if you haven't already done so, remove the engine drain plugs letting all the water/AF out of the block. This is absolutely necessary. your engine block needs to be empty. The AF is just insurance for any little water that may be trapped. Probe the holes to make sure no rust or scaling is blocking them. Put your drain plugs and your bilge drain plug in a zip lock bag taped to your steering wheel. I'm not familiar with your particular engine. You need to find out how many drain plugs there are and make sure you don't miss any.
Pull your thermostat and pour AF down there until it spills out of the block drain holes. You may also need to pour AF down some or maybe all the hoses that attach to your thermostat housing.

You should also change your stern drive gear lube. If water happened to get into there, it will freeze and wreck your drive.

Most of the pros here will tell you the AF is not needed because "air don't freeze". They've been doing this for many years.
I'm just a super cautious guy and like the extra insurance, so I spend a little more and run the AF through it and then drain it.
 

poconojoe

Lieutenant Commander
Joined
Sep 10, 2010
Messages
1,966
I assume your engine has a belt driven water pump. You need to drain the pump's lower hose. Mine (4.3L) has a drain plug at its lowest point, so I don't need to remove the hose.
 

CardiacKid74

Recruit
Joined
Jul 10, 2018
Messages
5
Thanks for the tips. I'll drain the plugs tomorrow and I planned on changing the lower gear oil tomorrow then pulling the batteries and putting the tarp on. Since posting i found a mercruiser manual online and watched some YouTube videos and see where the plugs are.
 
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