I am trying to winterize my 2 2001 or so 500 carbed mercs. I went to pull the drain plugs out of the block and there weren't any in there. All 4 are open. I stuck a screwdriver in the hole to see ip they were plugged and hit something solid about 1/2 to 1/2" into the hole. When the motors are running, there is no water coming out of them so i do not know what t do to drain my block.

Please help.

Maybe someone already sneaked in and winterized it for you.

You didn't find the right holes. There are holes as you described and there are drain plugs. If your boat has water pressure gauges they probably lead to drain plug spot. The stb side in front of starter may have a sensor in it as well. The plugs are not against oil pan but up about an inch they will face out perpendicular to the side of the block. They do not face down.
Jim

Found them, thanks for your help, MercMan you were right, the water pressure house is going to the drain and that is what fooled me.

Thanks for your help.

DUH!!! any fool knows that

I guess that makes you dumber than just any fool. You didn't know that either. Keep it up and I will go de-winterize your boat and you can do it yourself next time.

Make sure that you drain both sides of the block!! There is usually a petcock or a brass plug in there.

As an added pre-caution, after draining BOTH sides, reinstall all plugs and fill block with a good RV -50f anti-freeze solution. This will insure that hidden water in pockets are dilluted. Trapped water in blocks have spoiled many boaters welcome to spring of the new year. IMHO