MERCRUISER 3.0 Fresh water cooling tank

[fairshopperguy27]

I have a good used heat exchanger made by San Juan engineering for my 1991 3.0, I'm now looking for the coolant tank as seen in picture I attached. Does anyone know the OEM part number for this tank or where to get one? Any help would be Much appreciated!

 

[fairshopperguy27]

Just an fyi, its a 1991 bayliner classic that I'm installing a 1989 3.0 and complete Alpha one Gen 1 transom assembly and outdrive. Previously had a Gen 2 motor that was filled with water and seized.

 

[thumpar]

Was this a raw water cooled motor before? If so I would not go freshwater unless it has very low hours.

 

[fairshopperguy27]

Yes raw cooled currently. Why not convert?

 

[Scott Danforth]

if it has been run in salt, no use converting now. however if run in fresh water, you can convert. you simply need to pull the motor and clean out the water passages which probably have 2-3 # of sand and gravel in them or you will plug your heat exchanger.

I would pull the motor, mount to my engine stand, pull heads, turn motor over and using a flushing wand on the end of a hose, clean out the water passages.

however if there is significant rust and scale buildup in the water passages, I wouldnt waste time on adding a heat exchanger.

 

[fairshopperguy27]

Supposedly its a fresh water engine and looking at the outdrive and transom assembly I guess I'll buy that. No corrosion to be found. The motor is currently sitting on my garage floor. Do I really need to pull the head to flush it out? Couldn't I just pull the manifold, hook up water to the intake hose and flush it that way? Would like to avoid buying a new head gasket set. I run in salt water here in the puget sound so it would be ideal for me to have.

 

[Grub54891]

Just pull the core plugs, flush it, and install new brass ones.

 

[fairshopperguy27]

Just pull the core plugs, flush it, and install new brass ones.

This sounds feasible, still looking for info on the needed recovery tank seen in the picture. I have located the white plastic overflow tank.

 

[fairshopperguy27]

I'm going to answer my own question regarding the tank. I believe it is part # 96878A 2 - Reservoir Assembly. But thanks for tips on flushing the block before converting over to fresh water cooling. I would not have thought of doing that.