Re: OMC Winterize Method Flusing Muffs or Drain?
Either method will work if done properly, but you need to know what you are doing esp if you do the suck the antifreeze thru while you fog it method. The thing is first you have to warm up the engine on the muffs, and change the oil and filter. Then remove the flame arrester on the carb, warm it up again, make sure the thermostat is open (temp will be about 160 for an OMC) and shut it off. Next you have to quickly hook up the muffs to a full tank of antifreeze (5 gal), start it, and spray fogging oil in the carb before the tank of antifreeze runs out. As soon as it gets close to empty you shut off the motor. Then replace the flame arrestor and change the drive oil. This method allows you to do it without having to remove the drain plugs. The problem is if the thermo is not open all the way, you will not get all the water out of the engine. Also, if you do not shut it off before the antifreeze tank runs dry, you can ruin the inpeller in the outdrive. I prefer to drain by removing all the plugs and hoses from the thermo housing, then replace the plugs and fill the engine from each hose on the thermo housing, and then replace the hoses. Takes a little longer but less risky to the impeller.