I'm starting to second guess what we did when we winterized the motor prior to me bringing the boat home.

The boat had been on the water for about 45 minutes prior to adding plumbing antifreeze, but we immediately added the antifreeze after getting back to the house. After a little thinking about this, we didn't run the motor up to temp and the antifreeze may not have made its way into the block due to a possible closed thermostat.

At this stage it's impractical to perform this process again because the boat is in storage in closed quarters.

As an alternative I believe I should be able to find the block plugs, remove them and that should be sufficient to drain any liquid, water or otherwise, from the block. The components on the other side of the thermostat should be fine, as we did witness antifreeze coming from the exhaust.

Question at this point. Are there only 2 plugs, one on each side of the lower block about mid way on the engine? I'm assuming this is correct but hopefully someone can confirm my guess.

Until I get an answer, I guess I'll have to find a manual on the supra site to see if it indicates where these plugs are.

Damn, just came back from the storage facility after giving the trailer a little tlc. Replace the bearing seals on one side of the axles. The other side will have to wait until spring (no room to work)