Westerbeke Generator losing raw water Prime

Dani-Lu

Well-Known Member
Apr 20, 2007
1,352
Delray Beach, Fl
Boat Info
2001 410DA
Engines
3126 Cats
Current situation:

1. Have owned boat many years and never had issue with losing prime

2. i am able to prime by sticking garden hose in strainer and holding rag over top to create water pressure and have someone start generator.

3. Once started, generator runs fine. Pumps plenty of water and does not get hot.


Troubleshooting effort:

1. Noticed hose that goses from sea strainer to raw water pump had a bend in it approx 9 inches from sea strainer. Cut hose past bend and rerouted so it would reached sea strainer.

2. Primed with garden hose and ran generator and looked for a leak, but no leak found.

3. Shut off generator and looked for a water leak, no leak found.


Thought process:

1. Air is getting in at a high point, water goes down to strainer level and prime is lost.

2. Inside of hose is collapsing (not visible on outside of hose) causing the problem.

Next step: purchase new hose and install as the first step in process of elimination.

I don't think this is an impeller problem but if new hose does not resolve issue, then I would check impeller and then water pump. Trying to not go too far into forest on this one.

Thoughts from my CSR friends appreciated:
 
Could very well be an impeller problem. However, and I don't know if it's the same for your model, I've been told that a "garden hose" prime or forced flow winterization has a very good chance of flooding the manifold and getting into the cylinders. Be very careful with this procedure.
 
Check the siphon break in the exhaust line.....mounted high in the bilge near the generator with small-ish water lines running to it. If it leaks, salt accumulates in the valve and it leaks airs in when the generator is shut down which can cause the seawater side to also leak down to water level in the strainer. That means there is a big air bubble sucked into the water pump when you start the generator and there goes your prime.

Might not be the issue, but it is worth a look...........
 
Positive displacement pumps generally are self-priming. You have a different problem. Check for a vacuum leak in the strainer cap. It might not allow water to leak out, but does allow air to be pulled in. Otherwise, the impeller may be in marginal condition and not able to pull enough negative pressure to self prime. Odds are one of those two issues.
 
Had same issue with my westerbeke. Turned out when I pulled the strainer lid off the gasket from lid to strainer fell out. 20$ and a new gasket I was back in business. Took me 2 weeks to figure out what was wrong till I seen the gasket sitting under my mains. Even off it's there on yours change it out. It may be crushed or cracked
 
Thanks for the replies. I have not replaced the hose yet as I alluded to in my first post, and now my generator is holding the prime, at least while sitting at dock. Even though the strainer top does have the O-Ring and some sort of gasket as well, I will replace these easy parts first and wait and see if the issue reappears. Nothing worse than an intermittent issue. I prefer things to stay broke until I isolate the root cause!!!
 

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