Re: Running antifreeze through I/O engine ?
I find that way a bit expensive to do. Every year I open the petcocks on the side of the engine block to drain, then under the exhaust manifolds there is usually 1/4" pipe plugs that I take out to drain the water in them. After the water is done draining, I close the petcock, put the plugs back in and then remove the uppermost hose going to the thermostat. I pour in antifreeze until the gurggling is done and its filled to the top. Put the hose back on, then I take the hoses off the exhaust manifolds and fill them with anti freeze. It takes almost 2 gallons for a 4 cylinder, and in my 8 cylinder it took 3 gallons. And if you have a raw water pump, you want to make sure that it is drained and then filled. I personnally don't like the outdrive in a drum method. It takes alot of antifreeze plus with the engine running, the exhaust in the drum tends to spray antifreeze everywhere. I have taken the spark plugs out (which I do to put in a mixture of WD and gear lube for the winter) and then used the starter to turn the motor over until I see the antifreeze running out of the prop hub. But I have found that this is undue stress on the starter motor. That is why I do a direct drain a fill routine. I never have lost an engine yet using this method. Did loose a lower unit on a mercruiser once because I didn't lower the outdrive. Prop hub filled with water, froze, and broke. Well thats my opinion but I would suggest that you would be mechannically inclined and have common sense on how the cooling system operates in order to cover all those areas that are prone to freezing. Good Luck.