Westerbeke Generator

[PlayDate]

Oh contraire....

Then you would know that the impeller on a gas powered Westerbeke is a little over an inch in diameter and produces at best 1.5 psi of water pressure at its fully rated speed. It will more often destroy itself if water is not present at the pump inlet. Not a myth just a fact.

One of the engineering location issues with a Westerbeke is ensuring that the supply hose and pump inlet are at the correct level between the pickup and the pump inlet.

The OP has done a good job of eliminating the usual problem sources. My bet it is something simple with the pump.

Pumps on Westerbeke’s for the most part don’t go bad. If water is present at the pump inlet usually no/low pressure is the result of:

1) wrong impeller
2) an impeller that has spun on its hub
3) loose belt
4) a broken shaft which is very rare
5) an air leak

It is a frustrating job on his boat because there is not a lot of room in the ER.

 

[Peter 2405]

I'm now thinking a blockage is downstream of the pump. With a garden hose connected to the up side of the pump, there's enough pressure to force water through the system; but with the pressure build up from the impeller alone, there is not enough to push water through? Does this make sense?

 

[ttmott]

Then you would know that the impeller on a gas powered Westerbeke is a little over an inch in diameter and produces at best 1.5 psi of water pressure at its fully rated speed. It will more often destroy itself if water is not present at the pump inlet. Not a myth just a fact.

One of the engineering location issues with a Westerbeke is ensuring that the supply hose and pump inlet are at the correct level between the pickup and the pump inlet.

The OP has done a good job of eliminating the usual problem sources. My bet it is something simple with the pump.

Pumps on Westerbeke’s for the most part don’t go bad. If water is present at the pump inlet usually no/low pressure is the result of:

1) wrong impeller
2) an impeller that has spun on its hub
3) loose belt
4) a broken shaft which is very rare
5) an air leak

It is a frustrating job on his boat because there is not a lot of room in the ER.

But But But - you said "air lock at the pump". That is what I was taking exception to. These sealed vane type of pumps tend to be more akin to a positive displacement pump and always will self prime especially when their NPSHa is so low (the water level is inches from the pump inlet) . Unless inlet or outlet is restricted and the pump cannot draw it will always self prime so there cannot be an "air lock". It is the physics of these pumps.

 

[Peter 2405]

I'm going to run the pump again with a bucket attached to the suction line and gravity feed to the strainer, and remove the pump discharge hose. When I run the pump, if the pump is fine, I should get a good flow. If that actually happens, I would then think that I have a blockage downstream of the pump that the pump is not strong enough to over come.

 

[bone354]

Make sure the belt is tight enough. I changed my whole raw water pump and it work for a trip. Went to start it again no water flow looked quick to see if the belt was turning and it was. The belt wasn't tight enough move the pully. It looked like it was turning but once I climbed in there to see what was going on the belt was just spinning on pulley

 

[PlayDate]

I'm now thinking a blockage is downstream of the pump. With a garden hose connected to the up side of the pump, there's enough pressure to force water through the system; but with the pressure build up from the impeller alone, there is not enough to push water through? Does this make sense?

Yup. As I mentioned to my best OCD friend the amount of psi created by the impeller is 1.5 psi at operating rpm. City water pressure is 75 psi and most boat fresh water pumps are anywhere from 30-50psi so they will push water thru when the pump won’t. They can also backfill the cylinders and lock up the generator in an instant.

How many hours are on this generator? Also ….when was the last time it was running without a problem?