Flushing Merc 155 lower unit

[justplainbob]

How many of you guys flush your lower unit with RV antifreeze vs. lowering unit to make sure water drains out?

I have tried flushing lower unit by hooking a short hose up to the round mitts and pouring RV antifreeze thru the hose with the motor running, but it seems to take about 3 gallons before antifreeze comes out the p hole; most of the antifreeze comes out by the prop. Am I right to be worried about my motor getting too hot? Is there a better/more efficient way?

[boatfixer]

there is no need at all to even put anti freeze in there. the entire cooling sytem will drain with the engine in the down position.

[fishingstar]

you could causing more problems with your water pump. it needs a alot of waster to keep it cool. like boatfixer said it is made to drain.

Dan

[CAMAN]

The only boat motors that may need RV anti-freeze pumped into them is an inboard, and that is usually only if you can't remove all the drain plugs from it. Outboards with fresh water cooling are designed to drain all water from them when placed vertical and don't need anything else.