4.3 Mercruiser winteriziation - The "air don't freeze" approach

[Dante04SRT]

Well, last year I winterized my 3.0 by changing all fluids, adding StaBil and draining the block and manifold. Worked well, no problems.

Its finally getting in the 30-40's at night and I'm going to winterize the new boat with the 4.3 Merc.

I found 5 petcocks, 1 on each manifold, 1 on each side of the block and 1 on the front on the waterpump lower hose area.

Are these the only fresh water petcocks on the 2007 4.3 Mercruiser?

This boat does have P/S too - Whats the process for winterizing it? I heard there's a petcock on the cooler line - Do all P/S systems have the cooler? There are just 2 lines on my P/S pump, both look to be high press hyd lines.

Already added the StaBil and will have the outdrive all the way down.

 

[sundowner205]

Re: 4.3 Mercruiser winteriziation - The "air don't freeze" approach

The drain on the water circulating pump must be a new thing...one of the experts here will verify that.

The long hose that comes from behind your engine and goes to the thermostat housing is the raw water hose. That hose enters the PS cooler first. The PS cooler should be mounted on either the back of the motor, or under an exhaust manifold - down along the block. It should be mounted at an angle - if not you will have to find the drain on it and open it.

If the cooler is mounted at an angle, simply remove the aforementioned hose at the thermostat housing and lower it as much as possible. This should drain the cooler.

Also, disconnect the large hose coming from the thermostat housing that leads to the water pump at the water pump - the lower hose. This will drain the water pump. You can flush with A/F until it runs out of the block if it makes you feel better.

Best of luck.

 

[Gary H NC]

Re: 4.3 Mercruiser winteriziation - The "air don't freeze" approach

I always poured AF down the hose that goes to the PS cooler until it runs out of the drive.
Much faster than trying to get the drain plug off the PS cooler without breaking the darn thing..

 

[Lou C]

Re: 4.3 Mercruiser winteriziation - The "air don't freeze" approach

I always remove the big hose that goes from the front water cicrulation pump to the thermo housing, that drains a lot of water. I also remove the raw water intake hose at the thermo housing, and point it all the way down in the bilge, that will drain the hose and the PS cooler as well. The newer 4.3s have a drain, in the front edge of the intake manifold, it is a square plug. Make sure you remove this one too.
It's best for you to look at a recent manual from Merc to make sure you get all of them. The pic here is my old 88 OMC 4.3

 

[Bondo]

Re: 4.3 Mercruiser winteriziation - The "air don't freeze" approach

Ayuh,....

I'm not familiar with the newer drives,+ motors,...

But,.. As long as you get All the water out,... It'll be just Fine...