Winterizing a closed cooling 3 litre mercruiser (1989)

[skipbehr]

Is there information available on the forums about winterizing a closed cooling mercruiser 3 litre engine ?

 

[Bt Doctur]

same as any other closed system. Flush and fog the motor until it stalls, remove the drain plug from the raw water side of the HX and let drain, install plug ,fill raw water side with A/F.
Check the A/F side to make sure the freeze level is correct, spray motor to keep rust and corrosion to a minimum.
Place drive in down position, remove battery, cover boat.

 

[achris]

If the exhaust manifold on your engine is part of the closed cooling circuit, ignore step 2b. But if it's part of the seawater cooled section, you MUST do step 2b. Also, do not refill the system with AF. It's all copper and not subject to corrosion the same way cast iron is. (and I don't believe in refilling a cast iron block either, air doesn't freeze)...



Chris.........

 

[skipbehr]

Thanks for the quick response and information pictures were exactly what I needed.