Westerbeke Generator

[Peter 2405]

I had low water flow and high heat shut down on my generator on my 2001 Sea Ray 340. I cleaned my strainer and changed the hose from the sea cock to the strainer. Now I don't have any discharge flow. I then changed the gasket on the strainer and the hose from the strainer to the pump. Still no discharge flow. Hummmm, I then changed the impeller and the old one seamed in pretty good shape but I changed it anyway. There were no broken pieces. Still no discharge flow. Thinking that maybe there's an air leak I checked all hoses and primed the strainer from the point where the strainer hose connects to the pump. Still no flow. I also put a hose with a small flow from the garden hose into the hose at the sea cock valve, still no flow.

Can anyone suggest any other things I may look into? thanks

 

[superwa]

Since you mentioned that flow went from low to nothing after you replaced a hose, maybe that hose is defective? Also making sure that the hose to the pump has the metal jacket inside. That inside jacket can collapse under pressure, so the hose would look fine but the inside has collapsed when the engine is running.

 

[PlayDate]

You should have water flow from the raw water hose where it attaches to the pump. If you do not either the hose is blocked or the pickup is.

If you have a blockage on the hull pickup you need to close the sea cock and remove the hose. Using a 3/8” wood dowel rod, open the valve and push the rod down several times. If that was it….you should have a steady strong stream coming from the seacock.

 

[ttmott]

Seacock open? I've done it.... Everyone has.

 

[Peter 2405]

I've opened the sea cock and put the hose with a squirter attached to it, hoping that cleaned it out. Question? should the water from the sea cock flow freely, with force? It flows with out the hose on it, straight out of the valve, but with the hose on but disconnected at the suction right as it goes in the strainer there no flow, unless I push the hose down to the bottom of the hull under the strainer; then there is a slow stream, hummm. There's also no flow through the strainer to the other side, or with the cap off of the strainer there is no flow coming out the top.

 

[ttmott]

I've opened the sea cock and put the hose with a squirter attached to it, hoping that cleaned it out. Question? should the water from the sea cock flow freely, with force? It flows with out the hose on it, straight out of the valve, but with the hose on but disconnected at the suction right as it goes in the strainer there no flow, unless I push the hose down to the bottom of the hull under the strainer; then there is a slow stream, hummm. There's also no flow through the strainer to the other side, or with the cap off of the strainer there is no flow coming out the top.

Be careful to not flow water to the generator without it running. You will likely fill the cylinders up with water if you do.

 

[PlayDate]

I've opened the sea cock and put the hose with a squirter attached to it, hoping that cleaned it out. Question? should the water from the sea cock flow freely, with force? It flows with out the hose on it, straight out of the valve, but with the hose on but disconnected at the suction right as it goes in the strainer there no flow, unless I push the hose down to the bottom of the hull under the strainer; then there is a slow stream, hummm. There's also no flow through the strainer to the other side, or with the cap off of the strainer there is no flow coming out the top.

Great info. I still suspect the hull pickup is the problem. The generator hull pickup is located probably about 12-18” under the waterline so it does not have a lot of pressure but should free flow water. One way I can tell if the hull pickup may be clogged is to open the strainer cover and then open the seacock. Water should start overflowing the strainer immediately. If it doesn’t do that it is either the hose that connects the seacock or the pickup.

Both a clogged strainer feed line and pickup are common problems.

Once you have free flowing water at the strainer…..you should be back in business unless you have an air pocket at the generator pump.

 

[Peter 2405]

Great info. I still suspect the hull pickup is the problem. The generator hull pickup is located probably about 12-18” under the waterline so it does not have a lot of pressure but should free flow water. One way I can tell if the hull pickup may be clogged is to open the strainer cover and then open the seacock. Water should start overflowing the strainer immediately. If it doesn’t do that it is either the hose that connects the seacock or the pickup.

Both a clogged strainer feed line and pickup are common problems.

Once you have free flowing water at the strainer…..you should be back in business unless you have an air pocket at the generator pump.

John, thanks. How would I eliminate air pockets?

 

[PlayDate]

You need a length of 3/4" radiator/heater hose about 3-4' long and a funnel.

Disconnect the raw water hose to the pump and attach your hose in its place. Hold the hose above the generator and fill the hose with water and crank the generator over a couple of times. This will eliminate any air spaces in the pump and impeller. Then I open the seacock so water is flowing from the feed hose and quickly swap it out.

For some reason, Westerbeke's in many cases do not prime with just the raw water feed hose. My speculation is that the height geometry is the issue on some models or the impeller size itself. If the generator raw water pump inlet is above the height that water does not flow from the feed hose, then the impeller must create a vacuum which is pretty hard for it do being small. This is a common problem if the generator has been replaced and the pump is not in the exact same position. The good news is once the pump is primed you shouldn't have to worry about it again (for a while).

You can also attach the 3/4" to a 5 gallon bucket and run the generator to ensure that there is not a blockage after the pump. Sometimes......impellers lose their vanes and they end you creating a downstream blockage the pump can not overcome.

Once the impeller has water......unless there is a downstream blockage everything else should work okay.

 

[ttmott]

And when was the last time the heat exchanger was removed and tanked?

 

[dtfeld]

I think the end cap can be pulled with one bolt removed, right on the end. Should replace the gasket if there is one, but you can likely repurpose the old one until a new one is secured.

 

[Peter 2405]

I think the end cap can be pulled with one bolt removed, right on the end. Should replace the gasket if there is one, but you can likely repurpose the old one until a new one is secured.

End Cap? Please explain. thanks

 

[dtfeld]

I think most Westerbekes have a heat exchanger with a cap on it. Remove that bolt in the middle and it exposes the cooling tube where sea water flows thru. This is a likely blockage point in any marine engine. It might be blocked with marine growth, debris and likely impeller vanes.

 

[Strypes]

Gross.

 

[Peter 2405]

You need a length of 3/4" radiator/heater hose about 3-4' long and a funnel.

Disconnect the raw water hose to the pump and attach your hose in its place. Hold the hose above the generator and fill the hose with water and crank the generator over a couple of times. This will eliminate any air spaces in the pump and impeller. Then I open the seacock so water is flowing from the feed hose and quickly swap it out.

For some reason, Westerbeke's in many cases do not prime with just the raw water feed hose. My speculation is that the height geometry is the issue on some models or the impeller size itself. If the generator raw water pump inlet is above the height that water does not flow from the feed hose, then the impeller must create a vacuum which is pretty hard for it do being small. This is a common problem if the generator has been replaced and the pump is not in the exact same position. The good news is once the pump is primed you shouldn't have to worry about it again (for a while).

You can also attach the 3/4" to a 5 gallon bucket and run the generator to ensure that there is not a blockage after the pump. Sometimes......impellers lose their vanes and they end you creating a downstream blockage the pump can not overcome.

Once the impeller has water......unless there is a downstream blockage everything else should work okay.

Morning John,

So I took your advise, did just as you said with the bucket trying to prime, and even went a step further, to no avail. I opened the heat exchanger and found that the zinc had broken off but fortunately was still in one piece.
Using the bucket method; the pump would not "draw water" or discharge, however when I connected a running garden hose to the suction line downstream from the strainer directly into the suction, while the engine was running, it would discharge water and not over heat, telling me that their is no blockage from the pump to the exhaust. I also connected the running water up stream of the strainer so water would flow through the strainer. While the engine running I swapped the garden hose to the hose from the sea cock,(which had about 6" of water coming from it), the water flow from the exhaust stopped.

While the engine running and the garden hose connected, I started and stopped the engine several times thinking I could work any air pockets out the system. Still nothing.

I am confidant that there is no air in the system.

Things that possibly could stop the pump from pumping? (Your thoughts)

1. Air leak in the top of the strainer? I have a new cork gasket, maybe not sealing?
2. Gasket on water pump cover not sealing?
3. Is the inside of the water pump cover worn?
4. There was an "O" ring in the new impeller box, I didn't see were there was one to replace, Did I miss something?

Thanks for any advise.

 

[ttmott]

Besides eliminating the potential air leaks. It sounds at this point that the engine is not rotating the impeller. I suspect the impeller shaft has sheared (it happens) or the keyway/flats have rounded out. Or the key is missing if there is a key. Or even the wrong impeller installed....
Remove the pump cover and crank over the generator to make sure the impeller is turning.
And as an FYI rubber impeller pumps need no prime to draw water to debunk the air lock theory.

Lastly, I had a situation on my QSM 11 pump where the tech when I bought the boat tried to pound the impeller into place with a hammer and dinged up the sealing face of the pump. It had the tiniest air leak rendering that huge pump useless. It took us a month to get that figured out; ended up having to buy a new $900 pump.

 

[Peter 2405]

Besides eliminating the potential air leaks. It sounds at this point that the engine is not rotating the impeller. I suspect the impeller shaft has sheared (it happens) or the keyway/flats have rounded out. Or the key is missing if there is a key. Or even the wrong impeller installed....
Remove the pump cover and crank over the generator to make sure the impeller is turning.
And as an FYI rubber impeller pumps need no prime to draw water to debunk the air lock theory.

Lastly, I had a situation on my QSM 11 pump where the tech when I bought the boat tried to pound the impeller into place with a hammer and dinged up the sealing face of the pump. It had the tiniest air leak rendering that huge pump useless. It took us a month to get that figured out; ended up having to buy a new $900 pump.

When I installed the impeller I rotated the pully to make sure it rotated properly.

 

[PlayDate]

Morning John,

So I took your advise, did just as you said with the bucket trying to prime, and even went a step further, to no avail. I opened the heat exchanger and found that the zinc had broken off but fortunately was still in one piece.
Using the bucket method; the pump would not "draw water" or discharge, however when I connected a running garden hose to the suction line downstream from the strainer directly into the suction, while the engine was running, it would discharge water and not over heat, telling me that their is no blockage from the pump to the exhaust. I also connected the running water up stream of the strainer so water would flow through the strainer. While the engine running I swapped the garden hose to the hose from the sea cock,(which had about 6" of water coming from it), the water flow from the exhaust stopped.

While the engine running and the garden hose connected, I started and stopped the engine several times thinking I could work any air pockets out the system. Still nothing.

I am confidant that there is no air in the system.


Things that possibly could stop the pump from pumping? (Your thoughts)

1. Air leak in the top of the strainer? I have a new cork gasket, maybe not sealing?
2. Gasket on water pump cover not sealing?
3. Is the inside of the water pump cover worn?
4. There was an "O" ring in the new impeller box, I didn't see were there was one to replace, Did I miss something?

Thanks for any advise.

Depends on the model.....some use an O ring to seal the impeller cover plate instead of a gasket. It definitely sounds like there is a problem with the pump since you were able to push water through it. Do you have any pictures of your pump? Did water leak out of the pump when you had the hose feeding it?

Good work on narrowing it down.

The other issue @ttmott noted is the impeller or a shaft issue. I would definitely check the impeller again and make sure it isn't spun on its hub. With the cover off crank the engine to make sure the impeller is turning. It will be something simple maybe a loose belt on the pump.

 

[PlayDate]

Besides eliminating the potential air leaks. It sounds at this point that the engine is not rotating the impeller. I suspect the impeller shaft has sheared (it happens) or the keyway/flats have rounded out. Or the key is missing if there is a key. Or even the wrong impeller installed....
Remove the pump cover and crank over the generator to make sure the impeller is turning.
And as an FYI rubber impeller pumps need no prime to draw water to debunk the air lock theory.

Lastly, I had a situation on my QSM 11 pump where the tech when I bought the boat tried to pound the impeller into place with a hammer and dinged up the sealing face of the pump. It had the tiniest air leak rendering that huge pump useless. It took us a month to get that figured out; ended up having to buy a new $900 pump.

Clearly you have never worked on a Westerbeke.

 

[ttmott]

Clearly you have never worked on a Westerbeke.

Oh contraire....