What is this?

[Slayze]

I took off the exhaust manifold to fix the drain on this Volvo penta aq125a and noticed something that looks like it should be hooked up? Kinda looks like a hose barb. Anyone know what it is used for? I had motor running and nothing leaked from there so not sure what it is for.

 

[alldodge]

Reminds me of the supply to something like a water heater. Suggest removing the fitting and stick a wire in it to see if its just clogged with rust

 

[Slayze]

Boat was out multiple times last year and I had the motor running twice. Nothing leaking or coming out of this area. I will poke at it to see if it may be clogged. Still would like to know what it's used for. Can't seem to find anything on it.

 

[jerryjerry05]

Block drain. Open and antifreeze should come out.

 

[cptbill]

Could be a block drain or hot water heater never the less it's a hose barb that's into the water jacket. If you can't find anything that looks like it should connect there take it out and put a brass plug in. Two more things some engines had a Knock sensor and that would be a spot for it to screw into and also your engine temp. sensor could go in a spot like that.

 

[Mike Cuzino]

I took off the exhaust manifold to fix the drain on this Volvo penta aq125a and noticed something that looks like it should be hooked up? Kinda looks like a hose barb. Anyone know what it is used for? I had motor running and nothing leaked from there so not sure what it is for.

As Supreme Mariner stated, this fitting is a two-part cooling water drain valve. The smaller of the hex parts turns counterclockwise to unscrew and open a drain valve that drains the block of coolant water. The larger hex part removes the drain **** completely from the engine. The serrated barb allows you to push on a hose to catch the coolant in a container rather than draining it into the bilge.