[Glen]

I am new to I/O's and have a 4.3 Mercruiser with an engine mounted raw water pump. To flush the engine with water while warming the engine and to later add antifreeze to the system, do you do this via muffs on the outdrive or connect directly to the water pump for one or both procedures? I am assuming that to flush with water from a pressurized hose, you would use the muffs and to use a gravity feed system for the antifreeze you would connect directly to the pump but would like to hear some comments from those more experienced at doing this. Thanks

[Andy b]

Muffs all the way.
Otherwise you'll trash the impeller in the leg.

[Glen]

Andy, I understood that there would be no impeller pump in the outdrive if there was a motor mounted raw water pump. Am I wrong?

[Andy b]

What leg?
If it's an Alpha 1 then there's an impeller in the leg and a circulation pump on the front pulley of the motor.

[Glen]

I acquired this boat recently after a relative passed away, however, it is in storage and bubble packed at a marina up here in Canada so I haven't actually seen it. I have been told that there is definitely a raw water pump mounted on the engine (in addition to the engine circulating pump) so I believe the outdrive is a Bravo.

[Danish Mariah SX 18 Owner]

Here is my setup for winterizing my mercruiser 3.0 L
works without any leakage of anti freeze.

[Glen]

Great Pics. I have saved them to my Mariah file and will definitely refer to them for future flushings. Thanks very much.

[Danish Mariah SX 18 Owner]

You are welcome,
Plase note!, that its important that there is enugh flow thru the hose, and there is a second air vent hole in the antifreeze container, otherwise you will ruin the impeller!

i also have the drawing with measurements, for the cardboard plate, used under the haul on the picture
i wlll post them later here,