Resurrected!

[Dave Neptune]

Cory, first pull the hose off the pump and then open the valve to check the flow. Often times if you have a fairly straight shot you can poke it clear with a coat hanger wire or such. The intake "screen" if so equipped can easily get plugged in that time. Got to get wet to poke and scrape that.

Dave Neptune

[JOHN COOKSON]

N57
Also, try priming the pump.

ex TRUE GRIT

[nacra57]

Water Blockage

Ok. I finally made it out to the boat and confirmed that the water pump is working properly. However, there is still NO water coming out with the exhaust. I think there is a blockage after the water pump. Should I replace the hoses after the pump? I suspect the small transfer hose on the top of the motor. Any advice welcome.

Thanks!!

Cory
1978 C27

[nacra57]

Water Blockage

Is there a thermostat that is preventing water flow?

Thanks,

Cory
1978 C27

[Mo]

Hi Cory. What did the old impeller look like when you removed it. Wondering if it was all there or if parts were missing.

There are a couple of things you can check but this one might be a bit more complicated as you got the boat and might not be sure what was tried previously. Maybe someone before you destroyed an impeller in it and if that is the case there could be a blockage at an 90 degree turn elbow heading into the engine after the pump. Crud could also have built up or even rust flakes could be the culprit.

If it was my engine and I was in your position I'd do this...first.
1. Remove the hose that comes from the end of the exhaust manifold to the to hot exhaust. Turn engine over and see if you have water coming out there.
2. If there is no water there I'd get an air compressor down there, remove the pump and blow air back through the system from the end of the exhaust manifold. You would just put a rag around the tip of the air gun and hold a seal. Have a guy looking at the pump connection hose to see if anything comes out. Could be something in there from a previous owner who tried to fix it before you. Sometimes flakes of rust can block things off combined with crud, as well...I've blow back a few diesels just as I said and cleared them. Whatever is blocking might come out. There should be air just blowing out those lines where the pump was on there.

There is also the possibility of the water injection spigot on the hot exhaust is blocked solid. I have seen that a few times on engines. If you have water at the end of the manifold my next suspicion would be the spigot is completely blocked.

If I was to take a guess, blocked spigot. Another thing I've seen and I even have an old engine in my garage with one...a mixing elbow on the atomic 4. Those things are notorious for rusting closed on the water injection side.

I hope that helps...give it a shot.

[nacra57]

Water Blockage

Mo,

The previous impeller was intact when I replaced it, and the previous owner said it ran fine with no blockage. Unfortunately, it has been sitting idle for 4 years. I just had a compressor down there and blew out the intake side of the water pump. I will take your advice and systematically check the flow after the pump.

Thanks for the help!

Cory
1978 C27

[Mo]

You need to blow backwards. Sometimes flakes of rust etc. First see if you have water off the back end of the manifold ..then you would know water is getting through the block and the blockage is before or after that. Another place that blocks up is right at the aft end of the manifold. Again, little to no water will come out when you turn it over with the pump on...people have poked through carbon many times to clear that....so I'm thinking either a piece of debris caught up in an elbow, blockage at the end of the manifold (or completely full of crud) or the spigot rusted and carboned up.

If you find that it was at the end of the manifold your best bet is to then remove the manifold and clean the whole thing out. Like I said earlier, 4 years is a long time especially when it was in the water.

[nacra57]

Water Blockage

Thanks, Mo.

I will start with the water line on the back of the manifold and check for flow. We are pulling it out tomorrow for bottom job. It may be a few weeks, but I will reply with the outcome.

Thanks!!

Cory
1978 C27