Originally Posted by mmwjr
What you did should be ok however I would have used the shop vac to suck the water out and then back filled with antifreeze. The reason I say this is because the way you did it you are pushing water back through the raw water pump in the outdrive which has vanes that seal against the housing which may not allow water to pass. In suction you would draw trapped water out. This will be a small amount of water and the antifreeze will mix with it but loose some strength.
Well, the water only comes out if air can get in to take its place. That means either air goes thru the impeller in the normal direction or water goes out in the reverse direction. In my case, the impeller will be changed for normal maintenance some time this winter.
re: the rest of the process, I left the fuel tank @<1/2 as we will be in there this winter when replacing the floor. I first ran the engine till warm to warm up the oil. Then changed oil and oil filter along with the fuel filter/water separator. I treated the fuel with Stabil and ran for 5 minutes then fogged it. I did all the regular recommended things, drained the block, the manifolds and even tried to drain the risers. They were already drained but I tried anyway just to be sure. I removed the high end of all coolant hoses (except the PS cooler as mentioned) and backfilled with antifreeze. Drained and filled the outdrive gear lube. Still have the battery connected at the moment as I need to raise and lower the outdrive when moving it into the final storage location.