Flushing the fresh water\antifreeze - not so easy - 2015

October 2015 - At private slip in Nuevo Vallarta in Banderas Bay, Mexico

 We are now doing our Beta Marine engine maintenance and are having our first problem. How to get the old fresh water\antifreeze out of the motor. So now for new ideas. 

We wrote into the Beta Marine Engine Forum.

"We have never had an overheating problem and our Beta 38 is running great. FYI - If you notice over spry it is from me painting the engine at time or two touching up.

Ok so at 250 hours we checked the heat exchanger stack tube. We were at anchor in Barra-Bahia de Navidad, Mexico. I had a hard time getting the stack tube back in and it took a few tries before I could get it not to leak. Each time I think I was contaminating the fresh water\antifreeze with salt water. Not sure if that is the case or not. Perhaps you could tell me it is not so J Amway now we have 650 hours on the Beta 38 hp motor and we are trying to drain the fresh water\antifreeze out of the motor and there lies our problem.

When we did the stack tube we tried to drain the fresh water\antifreeze out of the motor using the petcock on the block. It was clogged so we unscrewed the handle and poked a wire in it and some came out. Not much. So we gave up and added new fresh water\antifreeze. We have noticed the radiator cap has some foam on it and wondering if it is from contaminated fresh water\antifreeze.

Our setup may look a bit different as we have dual alternators from the factory. They moved the oil change pump to side of motor.

So with the petcock clogged again we thought we would disconnect the hose on the engine block coming from the water heater and accumulator tank and back to the engine. This hose is on real good and we would need to cut it off. So that is not what we want to do and it is not as low as the petcock so some fresh water\antifreeze would be left in the block.

At this point I am thinking maybe we take the hose that goes to the water heater which is much easier to get at off and then drain what we can. Then re-fill with fresh water\antifreeze and run the engine and then do it again.

Would this do the trick of replacing the fresh water\antifreeze?

Are there any other better ideas out there?

Is this normal? "

And the answer is:

"Your anti freeze mixture is much too rich and this is causing your problem. As you are in a hot climate I suggest that you use a mixture of 40% anti freeze and 60% water.

50/50 is too rich for a hot climate unless you change it every 2 years. The clumps that are shown on the radiator cap are coagulated anti freeze, not salt water.

I suggest that you do your best to flush out the cooling system a few times when you get to a reliable fresh water supply and then fill with 40% A/F. You are better off draining the system from the hot water heater hose that not at all. Don't forget that the hot water heater will have much the same stuff in the heating coils as this is also part of the engine's cooling system."

So now the work begins on flushing out the system. Also in determining how much is still left in the block. Also flushing out the hot water heater and hoses.