Why no exhaust water

ashtead

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Started the engine today and no water came out. Checked filter which was clear so have replaced impeller which seemed visually u damaged. Have primed via water in clean filter and blown air down pipe to seasick and it bubbled out so now stumped so any thoughts on what next?
 
Take off the outlet hose from the pump. Turn the engine over briefly. Does water come out the pump? This will prove the inlet is not blocked and the pump is pumping ok. Put it all back together if there is still nothing coming from the exhaust you you have a blockage further down the line. Could somewhere around the thermostat. Unusual to have a complete blockage and no water at all getting through.
 
Started the engine today and no water came out. Checked filter which was clear so have replaced impeller which seemed visually u damaged. Have primed via water in clean filter and blown air down pipe to seasick and it bubbled out so now stumped so any thoughts on what next?

Is the engine direct seawater cooled or indirect through a heat exchanger?

Richard
 
Carefully check the integrity of the rubber seal, which you probably have, on the top of the water strainer. If it can leak air in, the pump will not lift. Try smearing some Vaseline on it.
 
I had the same problem on relaunching. Check the faceplate on the raw water pump. It needs to be smooth to create the necessary vacuum. Mine was slightly worn by the impeller and a bit crusty too. A couple of minutes with some 400 wet n dry did the trick.
 
thanks for views. I used a canister powered foghorn to blow air down from the seawater filter out through the seacock. Have refitted the strainer top and did check for damage to seal but will revisit. Will try seeing if comes out the pump exit pipe as suggested but speed seal plate on pump seems fine and replaced seal
 
thanks for views. I used a canister powered foghorn to blow air down from the seawater filter out through the seacock. Have refitted the strainer top and did check for damage to seal but will revisit. Will try seeing if comes out the pump exit pipe as suggested but speed seal plate on pump seems fine and replaced seal

A real puzzler.

Two suggestions.

Remove the pipe from underneath the seawater filter which goes to the pump and get someone to blow your air canister (good idea that) into that pipe. Listen / feel at the exhaust outlet. This will confirm a clear water run.

Run the engine for a few seconds with the Speedseal plate removed. It's a long shot but it will confirm the entire pump / impeller / drive belt/sprocket integrity.

I did the second test with one of my engines once but the problem turned out to be a leaking rubber O-ring on the filter top. A dollop of red rubber grease soon fixed it.

Richard
 
Problem solved . Having tested various pipes by disconnecting and filling up via a funnel this showed a leak in filter top caused by poor fitting seal on filter and having re fitted seal and applied Vaseline as suggested this fixed problem after prime with tap water and jug. Thanks to all for thoughts and advice
 
There's not many problems that Vaseline won't cure!
Thanks for letting us know the result, we're often left dangling. Glad it was something simple and cheap.
 
Something to bear in mind for the future:

Be very careful if you use a foghorn canister as a source of 'compressed air'. It might not be and usually isn't!

Most all the canisters that I have ever seen are filled with Butane which will readily burn if it comes in contact with sparks or a lit cigarette.
 
Problem solved . Having tested various pipes by disconnecting and filling up via a funnel this showed a leak in filter top caused by poor fitting seal on filter and having re fitted seal and applied Vaseline as suggested this fixed problem after prime with tap water and jug. Thanks to all for thoughts and advice

That's great news. Same solution I had last year.

However, and I don't mean to pour a dampener on things, but vaseline (i.e. petroleum jelly) is the wrong stuff and will almost certainly deterioration of the rubber seal and dry out in due course as well. It's OK short term and worth doing to resolve the issue but as soon as convenient you would be best advised to wipe it off and use proper silicone grease or rubber grease.

Richard
 
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