OMC Winterize Method Flusing Muffs or Drain?

I have a 93 Four Winns with a 4.3 OMC Cobra Drive. I was planning on using a winterizing kit and flushing the engine with Anti-Freeze via the intake muffs.<br /><br />However, when I looked at my engine manual it says to remove the drain plugs to remove the water. Also I noticed some people suggested removing the drain plugs and then filling various hoses with antifreeze.<br /><br />Which method is best? Would simply flushing the engine with antifreeze work

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.

Re: OMC Winterize Method Flusing Muffs or Drain?

I have used the 5 gal tank/kit method for a few years now and it is great.Make sure the kit that you get has a change over valve so you can switch over from water to antifreeze by turning a valve on the antifreeze tank.2 people makes it less risky.After you have run on the water side of the valve bring the motor up to operating temp so the thermo opens,switch over to antifreeze and be prepared tp fog as the other person keeps track of how much antifreeze is left in the tank.What I do is keep a coffee mug filled with marvel mystery oil next to me as I am spraying fogging oil into the carb.When my wife calls out to me that the antifreeze tank is down to the last gallon ,I pour the marvel into the carb while spraying fogging oil, in one quick shot and this stalls the motor out.DONE!!Charlie

Re: OMC Winterize Method Flusing Muffs or Drain?

Dont worry about the thermostat staying opened because when you switch over to antifreeze it is being drawn into the o/d at a slower amount than the garden hose forced water was so the engine temp will climb.Charlie

Re: OMC Winterize Method Flusing Muffs or Drain?

Thanks for all the advice. The flushing method is what I'll try. Also any advice on fogging oil. I bought a can of the type that comes in a aerosal can but also notice SAE20 oil can be used. Not sure if the aerosal can can spray enough into the carb to stall the engine at the end.

Re: OMC Winterize Method Flusing Muffs or Drain?

For the fogging oil, buy 2 cans and you can be a 2 fisted shooter also I find that if you use the little straws that come with them it severely limits how much comes out. I just shoot straight from the can and have never met an engine yet I can't stall as long as RPM's aren't too high)