Impeller

[Bruce53]

This thread started improperly in the Outboard section:

More disaster: the impeller was almost gone, all vanes in many pieces, most tiny, some an inch long. I could find only about a third in the intake area. I will see what I can find tomorrow when I visit the boat again although I have no idea where they could be. I installed a new pump today but will wait to see how much debris I can find before I put it back in the water. Is there any special technique I could use here? Sure would like to know what happened -- the pump ran fine before the overhaul....

 

[Reel Poor]

Re: Impeller

We need a little more information.

What motor and drive system
Serial #s
What year

 

[Bondo]

Re: Impeller

Back Flushing the system from farther Up-stream should Help.......

Don't Reassemble it, til you've found ALL the pieces,.....
Or,... You'll probably be taking it apart later to find the rest......

 

[Bruce53]

Re: Impeller

The boat is a 1986, four cylinder, 140 SVC 195 SS Stingray which, dispite all heresy, I converted to a great fishing boat for the Monterey Bay. It has a Mercruiser power unit, Serial A509505, with a GM head. I pulled it to pieces and replaced all bearings, had valve job done and a re-bore on all cylinders, new pistons, new header and elboe. I removed the stern drive, of course, but did not detatch the lower gear housing. It had never overheated before the re-build so I did not think to replace the pump -- big mistake. Somewhere in the assembly, I screwed up and, when I did the sea trial tied up at the pier, it overheated. I shut it down and, when cooled, I detatched the hose from the outdrive pump at the thermostat house and ran it again. No water. When I opened the outdrive pump there was nothing left. See first post above.....

 

[Bruce53]

Re: Impeller

Back Flushing the system from farther Up-stream should Help.......

Don't Reassemble it, til you've found ALL the pieces,.....
Or,... You'll probably be taking it apart later to find the rest......

BUT BUT How? In the re-build process I ran it on a garden hose for a time which could have blown the debris all through the engine and header and I see no way to "back flush" anything. In any case, I see no way to determine how many of the pieces managed to go through the system and were discharged, how many are lodged in the head, the block, the header and the elboe. The problem is with the timing; I don't know in all the processes when the impeller broke up. If right there at the pier, then the parts shouldn't have gone very far since there was no water flow. But who knows.....

 

[Bondo]

Re: Impeller

The Debris usually gets hung up in the transom tube or the P/S Cooler, or possibly the T-Stat Housing.....

If you open up the T-Stat housing,+ Check the T-Stat,....
Back Fush it right there with the Hose you had off before, Out thru the Impeller tube....
Do this with the lower unit Off the Drive,........

 

[Bruce53]

Re: Impeller

Did a full front-end disassembly: T-stat, T-stat frame, re-circulating pump, header cap. Removed both halves of outdrive. Flushed out water line from outdrive. No parts or pieces anywhere. Would have though that they fell out of the bottom of the outdrive where I found a third of the pieces except for the grill there. My guess is that they are all there together in the bottom of the block and will so remain. After re-assembly, I ran it in the bay for an hour with no problems apparent. So, looks like all's well on the western front and I will enjoy the opening of salmon season in two weeks. I hope....

What is a P/S cooler?

 

[Gary H NC]

Re: Impeller

P/S is the power steering cooler....8)

Glad all is running well now with no overheat!

 

[Bruce53]

Re: Impeller

Cooling system is fixed and doing fine. New problem: water in the outdrive. Not cream emulsion, as in an old leak, but separate water in the bottom half of the outdrive. I drained it out, about a pint, and then filled the top half with fresh 30 weight oil. Then I saw that oil was dripping out of the cavity between the two halves of the outdrive, can't tell exactly where it is coming from. I am sure I had a new o-ring on the top of the drive shaft and a new little o-ring on the oil passage between the top and bottom half. I am thinking that the shaft o-ring might have been displaced when I reinstalled the shaft. What is the best guess of you experts?

 

[Bruce53]

Re: Impeller

Cooling system is fixed and doing fine. New problem: water in the outdrive. Not cream emulsion, as in an old leak, but separate water in the bottom half of the outdrive. I drained it out, about a pint, and then filled the top half with fresh 30 weight oil. Then I saw that oil was dripping out of the cavity between the two halves of the outdrive, can't tell exactly where it is coming from. I am sure I had a new o-ring on the top of the drive shaft and a new little o-ring on the oil passage between the top and bottom half. I am thinking that the shaft o-ring might have been displaced when I reinstalled the shaft. What is the best guess of you experts?

 

[Don S]

Re: Impeller

You obviously don't have a clue how to put oil in the drive or anything about a Merc outdrive.
You shouldn't have 30W oil in it at all, and you can't fill just the top half.

You really need to read this service manual.
http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf

 

[Gary H NC]

Re: Impeller

please read the manual link Don gave you!
30W in the drive?,,,:%

 

[Bruce53]

Re: Impeller

Ok... but no power steering on this fishing boat. Thinking about getting one because it is required for an autohelm and I need that for solo fishing in the ocean. Anyone know of an easy (cheap) way to hold a trolling course while bringing in a salmon, please advise....
But... very rough starting. Believe it runs on three of the four cylinders with lots of smoke until warmup when it smooths out and runs very well. I warm it at about 1000 rpm. At warmup (a bit more than one minute) it smooths out and increases rpm to about 1200 rpm. I checked compression, timing and gas pump pressure. All ok. Would a vacuum gage show anything more? Wondering about lifters and sticking valves. Any ideas there on what to blame first would also be most appreciated.....
Thanks guys..

 

[Gary H NC]

Re: Impeller

If it was me that boat would need a bunch of stuff fixed before i thought about going in the ocean.
So what about the gear oil leak? Get the drive fixed then start trouble shooting the rough running engine..

 

[Bruce53]

Re: Impeller

Don......Thanks for the manual. Should have had it when I started this thing -- so I screwed up. Not the first time. The 30 W was the oil I always used in my old Bayliner and since Merc wouldn't tell me what their special "Silver lube" stuff was, I fell back on habit. Not near a Merc dealer so can you tell me if I should be using a gear lub or heavier engine oil? I realize I should pump up the lub but I didn't have a pump and, since there is a passage between the two gear housings, I figured it would drain down eventually and I would check the level later in case of air pockets....

 

[Gary H NC]

Re: Impeller

Air pockets cause gear damage.It must be filled correctly.Any 75w-90 gear lube would be better than engine oil! Get the Walmart marine gear lube or any marine lube from the auto parts house..GL-5 rated,75W90

 

[ziggy]

Re: Impeller

i understand yer merc dealer is a ways away. but he might have a $10 hokey pump for ya. it screws onto the top of yer merc gear lub bottle + screws into yer lower fill hole on the drive....made of much plastic. but it works.........

 

[Bruce53]

Re: Impeller

Thanks guys... I'll do it..

 

[kcski@sbcglobal.net]

Re: Impeller

Ladies and Gentlemen, I have a 1996 Cris Craft Concept 18 and 18.5' runabout, with a 5.0 mercruser engine and a Cobra SX out drive. The raw water pump is located on the front of the engine block. I would like to change the impeller but would like advice from someone who has done this. I removed the 3 screws holding the cover w/ 2 hoses attached and now I am looking at the impeller. I cannot pull the old one out with my hand. Do I need a special tool ? How hard is it to remove this impeller.

 

[Don S]

Re: Impeller

First of all, start a new thread with your question, don't just hijack someone elses post with your question.

Second. Register properly and don't use your kcski at sbcglobal dot net as your screen name or anything else unless you are wanting lots of spam.
Notice, your question has no name, location, or number of posts....... somehow you lost it all.

Third, yes, there are answers to your questions. Just not in this thread.