Electric bilge pump not working

I had been meaning to check this for the best part of 3 years now - pump whirs OK when activated, but would it work when needed?  Yesterday, after a great sail on Sydney Harbour (sorry for you northerly northern hemisphere guys), we decided to check it.  Unscrewed the pump from it's seat on hull, slid tupperware container under, filled with water, NO GO! It happily pumped maybe half a litre, then stalled - impeller still whirring, but nothing through the thru hull.  Blowing hard did nothing but raise blood pressure.  We took it apart, as you may have, (from the wrong end in retrospect) - the non return valve is cunnningly hidden under the shower sump pump, which in turn was protected by jagged barbs of the frig evaporator, but was OK.  The hose as it passes through the aft bulkhead has a kink which partially restricted flow, but we think the problem was a blockage in the pipe adjacent to the through hull.  Hooking up my Par Max 3 deckwash pump, we were able to get water through the pipe, but the bilge pump was still not up to the task.  After pumping a fair amount of water into the bilge (with the tee where the manual and auto pumps join disconnected) we finally cleared the (apparent) blockage and it now works OK.  I read some previous posts, where pump failures were reported, I wonder if they failed under excessive back pressure?  But you are reporting no back pressure now? 

I wonder if you have a blockage at the end of the run, and are seeing the hose fill up with compressed air and water before it grinds to a halt.  A bottle brush up the thru' hull from outside may be in order.

It took only 2 hours of Karma Sutra positions to clear it - from the inside!

Please keep the post going and let us know how you go.

As electric bilge pumps are again back as a topic can anyone help with this one? The early 341 came with two manual bige pumps, one operated from inside the saloon in case it was required when battened down in bad weather, the other in the cockpit. The boat was also prewired for an electric pump, the wiring ending beneath the sole in front of the door to the heads. I have lifted the sole and had a look but there is no obvious route for the discharge hose. QUESTION, is there anyone out there with an early 341 (mine is Hull No48)who has installed the optional electric pump, and if so what was the route for the hose. I have only looked at this problem on and of for FOUR YEARS,
Help

Many thanks Interlude, I had cocidered swopping the internal manual pump for the elactric one but I do like the idea of the internal manual. I can extend the wiring run no problem simply by drilling through one of the floors,or utilising the cable ducting in use to the fridge, the transom manual pump is midships by the keel bolts, the internal manual is to starboard of that. To date all that is the bilge is dust, but I seldom have a crew so the idea of an elactric pump is attractive
Thanks again

Hi Johan - I think I had a blockage which was able to pass air slowly, but which obstructed water flow - so when I started pumping water some flowed into the hose, compressing the air so that it seeped through (or just compressed), until the hose was full of water (or water and some compressed air), then the water stopped flowing while the pump continued to try to shift it.  So I think the blockage was at the "through hull" fitting, but having shifted it, I can't be sure - hence my suggestion to see if the manual pump works.  Also, check where the hose passes from the bilge into the aft compartment - mine is partially kinked htere - I am planning to slide a hose clamp down to that bend, and see if I can take the kink out with some gentle pressure, if that doesn't work I will install an elbow there.

Hi Johan - the Johnson 650 (which I also have) should be able to pump 53 litres/min with a 1 metre head.  I will retest mine next opportunity, but as I reported earlier it seems to be OK now I have removed the kink from the hose and cleared the obstruction.  I wonder if you have an electrical problem - can you check the terminal voltage at the pump when it is operating (>12V), or if you have an amp meter (or can fit it where you have the cable joint in your photo) you should see 3 amps.  Most handheld DVMs have a 10 amp range through a dedicated terminal.  Reading the current as well as measuring the voltage would be a good idea in case the float switch has excessive series resistance, as this would allow the external terminal voltage to remain at 12V even though the internal pump voltage was less.  Should be able to check tomorrow, will let you know.