Water no longer coming out with exhaust on 2013 R21EC

[DMcD]

We have a 2013 R-21EC that’s been in fresh water since we’ve owned it (6 years). Yanmar has 690 hours on it. Tried to take her out Sunday but noticed that water was not coming out with the exhaust as usual. Returned to slip and revved up the idle to higher rpm but still no water in exhaust. Gave up on boating and came back to troubleshoot. Replaced impeller (the old impeller was still intact, but was 2 years old so went ahead with replacement) to no effect. Confirmed hydrostatic water flow at antifreeze tap-off next to sea-strainer and that sea-strainer was clear. Disconnected hoses on either side of water pump and blew through, sensing no resistance in either. What’s the next thing to check?

Thanks for any advice.

 

[bob daily]

Exhaust elbow, lower 128370-13610
Mixing elbow, joint. 104214-13580
Gasket, exhaust elbow 128370-13201
Hatton marine & Industrial
4735 Shilshole ave nw
Seattle, Wa 98107
Phone (206) 283-5501

Or it could be your heat exchanger is plugged! You will have to pull the exhaust elbow to get to the heat exchanger so I would start there first
Best of luck troubleshooting. Bob

 

[bob daily]

A stupid question!
But is your raw water valve open?

 

[DMcD]

A stupid question!
But is your raw water valve open?

yes - i should have mentioned that was the first thing I checked

 

[DMcD]

yes - i should have mentioned that was the first thing I checked

A stupid question!
But is your raw water valve open?

I don't know if it's standard equipment, but my boat has a 'T' in the raw water line right after the sea strainer with a cap on it, which I use when winterizing to get antifreeze into the raw water side of the system. With that cap off and the raw water valve open there is enough hydrostatic pressure to force water up and out of that 'T'. This gave me confidence that inlet in the hull wasn't overly fouled .

 

[OverTime]

You never mentioned any temperature rise?

 

[DMcD]

good point. I don't have a temperature gauge. I think I can somehow show the temp on the helm console instead of engine hours - I'll look into that. The overheat alarm did not go off, but I did not run it very long once I realized water wasn't passing through.

 

[bob daily]

Before tearing things apart, I would check the water lock ( starboard side of engine compartment aft) looks like a gray plastic box) they are known to crack and leak into the bilge.
Removing a few hoses you should be able to narrow the problem down!
Usually the raw water will decrease over time and not stop all at once.
It’s a simple system from the sea cock to the strainer to the raw water pump to the heat exchanger to the mixing elbow to the water lock and then out the exhaust!
If you have water on one side and not the other I would guess that’s the problem!
Hope this helps you troubleshoot. Bob

 

[Newf]

VP D1-30 engine on mine so may not be applicable to yours but I had the same issue twice where it wouldn't self prime. Took the cap off of the strainer and kept strainer full with a bucket of water. It picked up and pumped out the water. Replaced the cap and it was fine after that. Not sure why it would not pick up from the short run to the sea cock but wouldn't on those two occasions. Good luck with your troubleshooting.