Noob question: where does the sea water enter the engine?

[Drcoffee]

Hello,
I am trying to get a better understanding of the water flow through the engine. I have a new to me, Mercruiser 5.7 carb 1995 Rinker. Is there a diagram of the cooling system?

I get the water is pumped up from the outdrive. Whats the next step.

second question about winterizing is do you store the boat with the anti freeze in the engine, or pull the drain plugs and leave it empty. if you leave it empty, do you prime the cooling system before start up in the summer?

thanks in advance.

 

[Bt Doctur]

If you locate a online manual those questions are answered
From the drive, thru a ps cooler, to the thermostat housing , thru the engine and manifolds and out the exaust elbow
There are many methods, some good ,some bad. Most flush and fog the motor till it stalls. Remove drain plugs and probe to insure draining hapens, never assume its empty because nothing came out. Air doesnt freeze but allows the cast iron to rust and scale. Filling with AF helps prevent that. Depending on your raw water system, remove the large hose from the thermostat housing, pour AF in until it comes out the therm housing, reattach hose. Remove manifold hoses and pour in until it comes out the exaust, do this for both manifolds. Shift into Fwd and remove drive, At the inlet hose at the therm pour AF until it comes out the back.
Optional, but highly recommended
check alignment, check gimbal bearing ,check drive oil and condition, grease U joints and shaft, reinstall,
In the spring, just hook up the muffs .No priming necessary

 

[Scott Danforth]

If you are tempted to buy one of the block buster 2000 or scam-co instant winterizing kits with a bucket to winterize.....dont

Drain all water

Then if AF makes you warm and fuzzy pour into the thermostat housing as indicated above

 

[tank1949]

Hello,
I am trying to get a better understanding of the water flow through the engine. I have a new to me, Mercruiser 5.7 carb 1995 Rinker. Is there a diagram of the cooling system?

I get the water is pumped up from the outdrive. Whats the next step.

second question about winterizing is do you store the boat with the anti freeze in the engine, or pull the drain plugs and leave it empty. if you leave it empty, do you prime the cooling system before start up in the summer?

thanks in advance.

Do what Bt recommends! Please understand that most Chevy V8s have block drain plugs on each side as well as exhaust manifold drain plugs. You may open these but due to internal rust over time, they may be plugged (not good.) Unplug!@ If you live in an area that has seasons and want to rest at night, fill with antifreeze but you may still have to drain risers via some method.

 

[Drcoffee]

I get it. I watched at least two dozen videos on winterizing. I liked the one from a mercruiser trained mechanic. drain out the water from block and risers and manifolds and power steering. To retard rust, refill with antifreeze. Got it.

At what point in the system does the water enter the water circulating pump? And does it exit the pump via the big rubber hose into the T-stat housing?

 

[Bt Doctur]

At what point in the system does the water enter the water circulating pump? And does it exit the pump via the big rubber hose into the T-stat housing?



Google gm v8 cooling systems

 

[achris]

 

[achris]

...second question about winterizing is do you store the boat with the anti freeze in the engine, or pull the drain plugs and leave it empty.

Personally I leave it empty, air don't freeze.
If you do want to put AF in, you MUST drain all the water out before filling with AF.

if you leave it empty, do you prime the cooling system before start up in the summer?

No requirement to prime, the water pump in the drive will fill the engine with water. It may take 20 or 30 seconds for the water to start coming out of the exhaust reliefs, but that's normal.

Chris....

 

[Drcoffee]

Thank you. Thats what I was looking for.

 

[Drcoffee]

Changing tac. I think its a good idea to replace the impeller in my alpha 1 gen 2 unit Before winterizing. Looking online, there are many kits available. Are there kits to avoid or preferred kits to look for? I am assuming I need the housing with the kit.

 

[achris]

Gen II has a stainless housing which usually doesn't need to be replaced.
I tend to use any brand of impeller, as long as it's Merc or Merc's accessory brand, Quicksilver...

And I usually don't buy parts until I open the thing up and see exactly what I need.

Chris...