Cooling Diagram

[SteveRay]

Does anyone have the waterflow diagram for the cooling system on a '05 4.3 MPI Mercruiser with an Alpha leg??

Thanks!

 

[Don S]

Re: Cooling Diagram

What is the SN for your engine? Is it raw water cooled or have a closed cooling system?

 

[SteveRay]

Re: Cooling Diagram

It is a raw water (open) cooling system....can't get the SN because she is away at storage....Is there more than than the open or closed?

 

[Don S]

Re: Cooling Diagram

The thing is, Mercruiser does nothing by year. Everything including changes in the system are done by serial number.
While you may have a 2005 boat, that doesn't mean you have a 2005 engine.
Things like manifold type, riser type, extensions, fuel coolers, drain systems such as multi-point drains, single point etc.
One picture dosn't fit anymore.

 

[SteveRay]

Re: Cooling Diagram

Found it in the operation, maint, and warranty manual....

OW 338768 (port)...not sure why they indicate port since it is a single engine craft

 

[Don S]

Re: Cooling Diagram

 

[SteveRay]

Re: Cooling Diagram

As usual....You da man Don!

Can you clarify which colors signify what?? I am trying to better understand the system for winterizing purposes....I am from the theory that if I fully understand something It can save me a lot of pestering others about other simple questions

 

[SteveRay]

Re: Cooling Diagram

So Don, is it safe to assume that by this diagram my engine is equipped with a "Cool Fuel" box?
can you explain a bit about then? I have heard nasty rumors of them

 

[Don S]

Re: Cooling Diagram

Basically, the blue is always flowing as long as the pump is pumping. This keeps the hoses at the end of the risers from burning.
The red is the engine and manifold cooling system, and is controlled by the thermostat for the engine, and the thermostat housing and the stat for the manifolds.
The green is for the drain system (Manual single point drain system)

Yes, you have the cool fuel. My condolances.