This year totally sucked for me, poor fishing,but most of all,I had a overheating problem. I consider myself mechanically inclined, but this year my engine put me to the test. I pulled the thermostat,replaced with new one, no luck,next I pulled the risers,cleaned them out bolted them back on,still over heating!!! now I didn't mention the lower water pump in the out drive, because I replaced that last year, when my problem started. To make a long story short I ended up pulling the motor, heads were blocked solid with rust in the water jackets, the block was the same way. Needless to say it was time for a complete rebuild, which I did myself, new heads, acidwash the block, complete reman!! Now the reason I'm telling this story is becouse I was told that Just draining the water out is not a good idea, because over the winter the cast iron rusts and over the years you get more rust and soon you'r in my shoes. The marinia I use for parts is a merc distributor for the north east coast, they recommend filling the entire engine with RV antifreeze, so there is no air in the system to start the rust mode. What do you guys do? PAP from PA.