When winterizing a mercruiser 6.2 with bravo drives, I ran anti-freeze throughout using the outdrive muffs until I had solid flow from the exhausts. I then "fogged" through the fuel filter using stabilizer and marvel mistery oil. Question is as follows: Is it O.K. to (or better or worse to) drain the block after all above is done using the remote drain hoses and leave those drain plugs out until next season, or do I need to just put the plugs back in now, or do I need to do it all over again and not drain it at the end? Thanks in advance for the input.

I always drain everything. I pull the drives every year and put them in my basement. This year I am pulling the engines so that I can do a little tinkering.

every winter we pull motors and drives outta the boats to tweak em a little. They all sit in our nice warm shop Plus it saves $10 on antifreeze


on others boats we winterize we just hook the muff system up and run about 5-6 gals of antifreeze through the system and shut em off.. good to go..

Just make sure the engine is warm enough to have your thermostat open.

I just winterized my boat this weekend. I drained the blocks when I was done, and I put the plugs back in. If you used a good anti-freeze mixture, it should be okay to leave it in the block, but I prefer to drain it out.

I heard a few years back of people doing that 2 cycle oil thru the filter thing. I checked with a few local shops, that all they do is clean and test injectors, and they all told me that running 2 cycle oil, mystery oil, or anything else that is not specifically made for injectors is Very bad for them. especially if it sits for a while, the oil can gum and clog the small injector orifis. They all said to run some Injector safe gas stabilizer and shut down. They did however agree that it's a good idea, but for the cylinder walls and rings, NOT the injectors. So now I just remove the plugs and spray a few seconds of foging oil. Then I rotate the engine a few revolutions and install the plugs.