Westerbeke pump query

[Graham Lorimer]

I put a new Impellor in my Westerbeke earlier this year, it has done 47 hours since and was perfect when I left the boat in September.

Gave it a run last night and there is no raw water pumping through the system.

Through hull tap is on, boat has not been anywhere, so a mystery as to why not pumping.

Can the system drain down and there not be enough suction to get going if left for a time?

I will strip it tomorrow and replace the impellor but just looking for advice as to why this might happen.

Graham

 

[mistercomputerman]

Look for a thru-hull fitting plugged with growth.

Remove the hose to the seacock and see if you have water flowing in from the outside.

Open the seacock and shove a long screwdriver down through the rushing water to clear away any growth.

Of course, you could haul the boat and do the same from the other side.

 

[fwebster]

In addition to the intake being fouled...........that is entirely possible, but it seldom stops 100% of the water flow.........there are 2 other possibilities:

1.The generator seawater system is completely empty and needs to be primed. That can be done by taking the boat out for a run or with a water hose filling the strainer to over flowing while you manually start the generator from the remote panel in the bilge.

2. The impeller has copper bound to the pump housing and you have stripped the impeller blades off the impeller. IN this case, a new impeller is required as is taking the cooling system apart far enough to retrieve all the bits if broken impeller blades that have travelled to the heat exchanger. Here is a copy of the Sherwood tech tips for your pump...note the middle paragraph where it describes copper bonding of the impeller blades to the pump housing:


To maintain best engine performance and to prolong engine life - replace your impeller annually.*

Three tips to help you install your new impeller:

•Use a non-petroleum based lubricant (silicon or soapy water) to help slide the impeller into the housing.
•Install the impeller with a twisting motion onto the shaft.Never force an impeller onto the shaft.The impeller
must be able to move freely on the shaft to properly prime and function.
•Use a small amount of non-petroleum based lubricant to help hold the o-ring when replacing the cover.

Proper storage of the impellers during a prolonged lay-up can help maintain the life of the impeller.
Remove the impeller from the housing and store in a cool,dark place.This will avoid the following:
•Copper bonding of the impeller to the housing
•Vanes "setting" into position as stored in the housing
•Ultraviolet deterioration

*See Maintenance Schedule on page 5
Genuine Sherwood TechTips