1503 Coolant Capacity?

[JrFiero]

OK, this sounds, even to me, like a stupid question.
I have a Utopia NA, twin 1503s (155hp). In the shop manual under Technical Specifications, Twin Engine Boats, Capacities, it says Engine cooling system "4.8 US quart total.' Not being used to working on baby engines, I assumed that meant 4.8 quarts per engine. But after adding my calculated amount of AF, I put in very little distilled water. Is it possible that each engine has only 2.4 quarts of coolant?

 

[ski-d00]

It's per motor, the heat exchangers hold half of it. Were they drained because it's difficult to get all the old antifreeze out.

 

[JrFiero]

Thanks for the reply. Makes me feel better about the amount of AF I put in.
I did drain from the exchangers, with the boat nose as high as the trailer jack will go. I noticed the drain plug isn't in the lowest corner of the exchangers and wondered how much difference that would make.
I put the cleaner and distilled water in, launched it and drove it pretty hard for a half hour or so, then let it soak overnight, ran it again then retrieved it, let it cool, drained it. "flushed" it with tap water, and refilled with the AF and distilled water. I was surprised when I drained the cleaner that it was so green, probably because the drain doesn't get it all, as you say.
So now I bet I have a little bit of cleaner left, some tap water, and then my AF and distilled water.
Is there a better way to drain and flush?
Thanks,
Jonas

 

[ski-d00]

You are leaving a little behind but it is mostly trapped air so not as bad as you think.

Other than disassembling everything, the only thing you can do is keep flushing it with pure water while running it for 3 minutes on the hose in between flushes to mix the solution until it is completely clear after removed and just water. When you refill, the system traps a lot of air. When you run it, most of the trapped air is removed if the thermostat opens. Then add 2.4 qts straight 100% antifreeze, not 50/50, then finish with water. Then run again, fill with more water to top off. Then lake test, you will have to add even more water to top off which finally gets all the trapped air out.

 

[gazzaskirepair]

Use coolant to top off , check the coolant bottle and it may say already diluted Do NOT add water