Exactly. Works like a charm.

so you fill the bucket with antifreeze and use a sump pump and pump the antifreeze using outdrive muffs through the seapump through the cooler and through the motor and out the exhaust and back into the bucket and run the pump continuous untill the antifreeze comes out undiluted wouldnt the antifreeze by pass the motor and straight out the exhaust if the thermostat is shut ? what about silent choice and antifreeze collection back into the bucket

Later

God I love closed cooling. Best boating money ever spent. Harbor freight pump, Rubbermaid container, pump until it comes out of the exhaust, walk away.

The engine needs to be run up to operating temp to open the thermostat (or remove it). You have to do that no matter what. You’ll have some dilution at first unless you drain the block prior to adding antifreeze. Just run it through until it comes out pure.

When I had stats briefly in my old boat I could never get them up to Temp to open up on the hose.....

You don’t need to if using stock merc tstat housing and circulating pump. It doesn’t close off anything per say, it just prioritizes (directs percentages) to block until tsat opens

since antifreeze is being heated and cycled…this will open t stat. Reason why it never opened on a hose is because it continuous cold water.

that’s not the case on a closed loop antifreeze tank.

agreed. t stats have holes around the perimeter allowing fluid thru. Albeit not a lot but it allows some.

the best method is just run them up to full temp to be sure.

yes run sump pump to muffs or fresh water hook up. Prior to using antifreeze, remove water plugs on engine to get most of the water out. We actually start engines for 10 seconds with water plugs removed. It burps water out. Put plugs back in and run it on antifreeze using sub pump. there will be hardly any anti freeze dilution.

for normal exhaust you can use pvc pipes with rubber boots for collection. For silent choice just put the bucket underneath the drive. You’ll lose some but not much.

After antifreeze is heated and t stat is open. Fog engine again using antifreeze loop. Shut her down, change oil and you’re done.

I took a video a few years ago…