Re: diy winterizing kits
This has been discussed many times before, do a search...
The short answer is NO it is not a good idea for a raw water cooled inboard or I/O, because if the thermostat does not open all the way, the AF will only get into the manifolds, the engine may have a very diluted AF/water mix or all water. Some people have run it to warm up, then removed the block drains and the big hose on the front of the engine to drain that area, replaced them and then ran it to suck in the AF. The other issue with sucking in AF is if the impeller is not perfect it may not pull it in, and it can burn the impeller and overheat the engine.
Keep in mind you do not need AF for freeze protection...it is for corrosion protection in stoage...
If you want to use AF for corrosion protection (and Merc and Volvo both do list this as an acceptable procedure in their manuals, so did OMC) the only safe way to do it is to drain everything manually and then back fill the engine from the big hose on the front of the engine, and the manifolds from their feed hoses off the thermo housing. Also you can fill the raw water intake hose after draining...
I have been doing it this way for 8 years and its safe, easy, no worries with the AF running out before you get it fogged and no worries about the impeller not sucking it in....
those kits can be used on an engine with closed cooling, but the same concern with the impeller apply, esp if it is a Bravo or Volvo system with the impeller way up on the engine.
