Mercruiser 4.3 ThunderBolt - Need help summerizing

[mike142]

93 Bluewater Riviera with an 05 Mercruiser 4.3 thunderbolt v6.

Had the boat winterized, and the shop pulled 2 ... plugs? One is the drain plug and the other is perhaps some sort of anode plug? But for the life of me I can't figure out where this plug goes. The shop is being beyond unhelpful, so hoping someone might know?

Pic of drain plug and the other mystery plug.

Thanks!

 

[dubs283]

One on left looks like garboard/hull plug. The one on right is possibly an anode plug for a heat exchanger. Is the engine closed cooled?

 

[Scott Danforth]

looks like an anode for exhaust or a heat exchanger

the anode looks like it needs changing too

 

[mike142]

Thanks guys ! I had it in my head that I was looking for something on the block, never thought to look on the heat exchanger (duh).