Raw Water Iimpellar!!!! Yikes!!! 2 of 8 vanes gone !!!!!

S

Sea~Lah

New Member
Aug 28, 2010
124
Buffalo,NY / Port Colborne, Ont.
Boat Info
1990 25ft Sundancer
Engines
7.4L Bravo I
I was in the process of reinstalling the two hoses at the bottom of my engine. Before connecting them I reached inside of the plastic water-pump cap. I pulled out pieces of the impellar. Great! Now what! (I just bought the boat(used), in the fall).:smt021

Well, I figured out how to remove the pump cap and motor. That's when I discovered the beaten up impeller . I also found that there was a piece of the plastic cap (bar) missing.

Question: Before I install a new water pump kit (on order), how can I be sure that all the old impellar material is removed from the hoses?
Does that stuff travel to the engine??:huh:

thank you for any suggestions!!!
 

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That's really bad! That motor had to be over heating. :smt018

It's important to find all of the pieces you can... but that looks like its been failing over a long period of time so you won't find it all.
 
Ouch! When you ran the boat most recently, did there seem to be waterflow through the exhaust port? I just went through something similar with my genset and I'm not sure if it was correct protocol, but I carefully used a plumbing snake to go as far as I could and didn't find anything. The local mechanic said that the small parts often wash through that type of system. More capable minds than mine will surely chime in shortly, but I feel your pain.
 
I only started the boat for about 10seconds in the Fall. The P.O. was a go-between for a charity group. When I was considering the purchase, he told me that the engine fired-up with no problems. Maybe he ran it too long????
 
Again, take my input with a grain of salt, but I would be inclined to snake the inlet and outlet as far as possible without doing damage. I would try to force water through the system with a water hose, both ways, to try and flush any debris. I would then replace the impeller and housing, confirm proper operation, and put it in the water with a close eye on the exhaust ports, my temp gauge and water flow meter (if yours has one built into the Smartcraft). If it isn't flowing, you'll know quickly.
 
Wow, that is pretty bad. Yeah, you're going to have pieces scattered all throughout your engine. Follow the output hose from the pump, you'll see it goes through some coolers and eventually makes it's way up to the t-stat housing. For good measure, I'd check all the coolers, but the t-stat housing is going to be the smallest "trap" for pieces. Pull the t-stat housing and check that, too. Might as well get a new t-stat and gasket while you're at it. It might not be a bad idea to pull (maybe replace it too, while you're there) the circ pump, too.

Can't worry too much about what's left in the block. Some will work their way out, other will be there forever. When you winterize, be double sure that you poke the drain holes. If you can remove the entire fitting, that might even be a good idea to see if any of the pieces are there.

Keep a watchful eye on your temps. Feel various areas for "hot spots" - a $40 IR gun would be a good investment.

Oh, and never run an engine without water. Once in a great while (if you have to) it's OK to turn it over. But it's better to be safe than sorry.
 
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that looks really bad. I would think that the small pieces will just float though the engine as long as you get the bigger chunks out. I have this fear of breaking down on the lake so whenever I purchase a new boat before I even take it out I replace the water pump on the motor, impeller, spark plugs, wire, cap, Belts, oil, gear lube and fuel filter. I take off the outdrive and replace the bellows and check the U-Joints, Bearings, and grease everything up real good, drain the block and hoses to get any sand that could be in the engine out, and then I dump tons of Sea Foam into the fuel tank to clean it out good. I also keep spare water pumps, impellers, spark plugs, belts, plugs for the block (I had one break off and flood the engine compartment once on a water test when I was looking at purchasing a boat). I know this seems like a lot but, you just never know how the previous owner took care of the boat. Most people don't replace things until they are broken. If you fix the common things that will break eventually, then you have a good understanding of your engine and its reliability.
 
Sea~Lah said:
I only started the boat for about 10seconds in the Fall. The P.O. was a go-between for a charity group. When I was considering the purchase, he told me that the engine fired-up with no problems. Maybe he ran it too long????
Click to expand...

If the engine was run with out water even for 10 seconds the impeller has no cooling and eats itself.
Never run with out water.
Back flush with water and replace the pump.
Good luck.
 
Jack2Tite said:
Wow, that is one scary obsession!

Your practice of operating the engine w/ the seacock closed until the impeller fails is foolish.

Is this the offensive advice over which you obsess?
The Mercury FSM for my engine states: Task: "Seawater Pickup Pump - Disassemble And Inspect", Interval: "Whenever Insufficient Seawater Flow is Suspected. (If Operating Temperature Exceeds Normal Range.)

This fully comports with my unwaivering, consistent advice that the pot head mocks, "inspect raw water flow at startup".
​
Click to expand...
3 posts illustrating your obsession with his obsession. Why you doing this stuff? A couple years of drama and I admit I personally gave you the benefit of doubt a couple times, maybe this is more fitting http://www.youtube.com/watch?v=RR3MHCH3tP4
 
Jack2Tite said:
Wow, that is one scary obsession!
Click to expand...

Who's the obsessed one?

As w i n g l e s s, your advice was to not change the impeller at a regular interval. Well champ, it looks like someone took that advice. Hence Gary's observation.

And BTW Pot, kettle is calling you on the black house phone. How many stalking posts have you made on other boating sites? Seems that the Hull Truth folks have finally figured out you are nuts. You can't change your stripes, so it is only a matter of time before you get your current avatar banned from here. I'm franky suprised Jim let you come back...

-CJ
 
Neither Jim, Chuck or myself let him back on, but we can't watch all the ip addresses he can show up from so when you find him, let us know and we will do our best to boot him. He is not now or will ever again be welcome on CSR.

Best regards
 
Sea~Lah said:
I was in the process of reinstalling the two hoses at the bottom of my engine. Before connecting them I reached inside of the plastic water-pump cap. I pulled out pieces of the impellar. Great! Now what! (I just bought the boat(used), in the fall).:smt021

Well, I figured out how to remove the pump cap and motor. That's when I discovered the beaten up impeller . I also found that there was a piece of the plastic cap (bar) missing.

Question: Before I install a new water pump kit (on order), how can I be sure that all the old impellar material is removed from the hoses?
Does that stuff travel to the engine??:huh:

thank you for any suggestions!!!
Click to expand...

This is a serious break down in routine maintenance. This impeller moved zero water, perhaps for some time. What you do not know is how bad was the over heating issue and how much damage has been done. I want to strongly urge you to try to find every chunk of those missing impeller blades. Lay the recovered pieces out like a puzzle and piece together every missing vane. Once you have found all you can, you will see how much is still in the engine recesses, the probable size and can begin a plan to recover from the disaster. That simple little chunk of rubber is all that is between happy healthy engines and $30K in useless chunks of metal. Gary @Four Suns has an excellent photo of his recovery from a shredded impeller, perhaps he'll repost it for you.

Since the history of this engine is unknown, you have to put together a known base line of condition on every major system element. Raw water is your first challenge. Then, Lubrication, then Fresh water cooling, then fuel filtration, then air cleaning, compression and exhaust, then power generation.

To know you will be on the water in a safe and dependable boat, you are going to have to do the work. This impeller belies potential serious neglect everywhere ...
 
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