Yanmar seawater exhaust bleeder plug

[maury]

I am confused. I have a brand new Yanmar (installed on landlocked boat 15 years ago) 2ym15. Recently pre launch I had a mechanic start it up and check it out. He told me to replace this with a solid plug which I have been searching for locally and now today on line.

What exactly does this do and why was a draining plug installed if a sold plug is needed. While awaiting the right plug can this draining plug be used and are there ramifications to using a draining plug temporarily? Engine is seawater/antifreeze cooled.

[ScottRhodes13]

I imagine that valve is used to drain the raw water from your heat exchanger if you expect below freezing temperatures. It's probably not necessary if you keep your boat in the water. I don't know why you'd need to replace it though... just keep it closed.

[maury]

Originally Posted by ScottRhodes13

I imagine that valve is used to drain the raw water from your heat exchanger if you expect below freezing temperatures. It's probably not necessary if you keep your boat in the water. I don't know why you'd need to replace it though... just keep it closed.

I am able to blow through the plug so I assume it always flows. There was a 14” clear hose going down to motor drip pan so I assume that it just always runs there. Notice the pan is filling with water from somewhere. Boat overall is dry so maybe it is from where the plug goes (which is presently out).

[ScottRhodes13]

Typically, a plug like that can be rotated or tightened to a position where it doesn't flow. I'm not familiar with that engine, though. You could probably use it for a while, as long as it doesn't divert so much water that the engine overheats. Looks like it may be below the waterline, so make sure to keep the seacock closed when leaving the boat.

[Turtle Blues]

That is a winterizing draining fitting it has no provision to be shut off and was never intended to be left in place during operation. your mechanic is correct. either replace it with an operable petcock or a plug before operating.

[skipperpete]

15 years of service and still in pristine condition! Screw it back in and use it as intended. It’s a bronze plug in a bronze endcap and chances are that whatever you find to replace it will only be brass which will de zincify eventually.

[Turtle Blues]

I may have misunderstood your statement about blowing air through it.
Does it seal water tight when properly seated in the housing - just snug with a wrench?
Sealed watertight is the goal. it is not supposed to be draining into the pan during operation.

[maury]

Originally Posted by Turtle Blues

I may have misunderstood your statement about blowing air through it.
Does it seal water tight when properly seated in the housing - just snug with a wrench?
Sealed watertight is the goal. it is not supposed to be draining into the pan during operation.

Your earlier post clearly explained it needs to be removed and plugged. For now while awaiting the correct plug in the mail can I just plug the connected drain hose with a screw? Is there pressure or just passive flow?

[Turtle Blues]

Pressure close to 20 psi possible
Bolt with hose clamp ok for temporary.

[SY Harmony]

In the pic attached, I marked an area in blue.
When you tighten the fitting into the end cap. The blue area seat against the end cap and seals water flow off.

I would KEEP the fitting over a plug. Simply because of the hose barb! That allows you to control the outflow of raw water when you have to drain it. This keeps your engine from getting a salt water bath.

[SY Harmony]

Originally Posted by Turtle Blues

Pressure close to 20 psi possible
Bolt with hose clamp ok for temporary.

In the raw water system? I don’t think so

[hlev00]

It will be worth tracking down the parts catalog, operations manual and service manual for the engine and the parts catalog for the marine gear. Having said that, the only place I see the plug/drain you are showing is in the parts catalog. It is odd that it isn't designed as a petcock or would show the correct plug to replace. A more careful read through of the docs might reveal more.

[maury]

I had also searched without luck. Hopefully parts places will be able to figure it out.

[Searles]

Did your mechanic say anything about the exhaust restriction with that metal elbow screwed into the cast iron exhaust injection fitting.⛵️⚓️

[maury]

Originally Posted by Searles

Did your mechanic say anything about the exhaust restriction with that metal elbow screwed into the cast iron exhaust injection fitting.⛵️⚓️

No, hmm. Should there be any cast iron connected with a marine engine. What do you recommend?

I have not been a motor person but have been gradually and now fully stepping up to the plate to care for this as best possible. Today, awaiting a price from parts place today on plug so I can order it and will temp install bleeder plug with hose plugged and clamped. Also about to balance the shaft.

For the shaft it has a red drive saver shaft coupling so assessing where measurement is taken with feeler gauge. My guess is before the shaft saver but will look at both sides.