Winterizing the Yanmar 1GM10 engine w/o starting?

[heath18703]

We usually winterize the engine by disconnecting the water intake line and running a gallon of antifreeze in before shutting her down. But long story short, this year we're doing some gas system maintenance and may have some trouble starting the motor before it gets cold.

Is there a way to possibly disconnect one of the lines that run toward the top of the engine and get antifreeze in that way?

 

[SailormanDan]

I have a 1 GM and I'm going to say "no" off the top of my head without having the Seloc or Clymer manuals in front of me. They have diagrams in them that show how the water circulates around the cylinder and if I remember correctly, the water comes out of the water pump and into the engine and goes both forward (front to back) and back around, and also left and both channels then exit out the mixing elbow. The pump would help force the coolant back into those areas and displace the water more completely than just pouring it in.
My original typewritten instructions don't reference anti-freeze at all, they just say to turn off the intake and "run it out", so possibly you could just turn the engine over with the starter and pump some through, otherwise pressurize the system somehow to force it through. Do a search on the site, a manual or diagram may have been posted that would give you a better idea.

 

[jviss]

Certainly.
You can pump the pink stuff in with an electric or manual pump, in lieu of the seawater pump running. I recommend draining as much seawater as possible. This may require removing some hoses. Don't forget to drain the sea water pump, the strainer, etc. I even drain the heat exchanger before filling with pink, to avoid dilution.

I should have asked, fresh water cooled or raw water cooled?

 

[kloudie1]

Ya can do that IF you remove the thermostat and plug the bypass line (little line from the t on the pump outlet to the thermostat housing. Then reinstall the thermostat housing.. then remove the hose from the water pump..remove the exhaust hose... then fill with antifreeze from the hose that you removed from the pump outlet. This fills it from the bottom up to eliminate air bubbles.. Fill until antifreeze comes out of the exhaust elbow.. Then drain the water lift muffler. Then loosen the cover on the water pump and drain it, leaving the cover loose until recommision. Any part of that not done may result in broken parts from freezing.