What happened to my impeller?

[i386]

I recently replaced the impeller on my '69 33HP Ski-Twin. It's been pumping water like a champ in the bucket until now. I was idling it and it stopped pumping while I was watching.

I pulled the L/U today to see what the problem was. The rubber impeller has seperated from the keyed brass part in the middle.

It's probably got about 2 hours idling time on it total. Never been ran above idle. The water in the "tank" has never been allowed to get hot. I did not "pinch" the impeller with the waterpump during assembly. It's never been turned ccw.

I'm glad I wasn't on the lake and really glad it never ran hot. Any ideas what may have went wrong?

 

[Paul Moir]

Re: What happened to my impeller?

That's not the first time I've heard of that happening lately. I think there are some defective ones out there.

Did the old impeller match the new one? Particularly the thickness? (it is real close).

Turning it CCW won't hurt it. The blades flip easily.

 

[OBJ]

Re: What happened to my impeller?

I would like to know if it's an OEM part or aftermarket. I have yet to have an OEM impeller fail like the posted failure....J/Rudes or Mercs.

 

[BoatBuoy]

Re: What happened to my impeller?

I also have heard lately of some doing that. I think they were Sierra.

 

[i386]

Re: What happened to my impeller?

It was a Sierra 183006.


I submitted an email to the online retailer I bought it from. I don't expect they'll swap it for a good one but you never know. I will try to find an OMC part to replace it.

As usual, thanks for the information. The guys in the Evinrude forum are top notch.

 

[F_R]

Re: What happened to my impeller?

That problem has been around for about fifty years. They never will learn, I guess. OMC once had the best impellers in the industry but even they have gone the cheap route in later years. And burned up a pile of motors.

 

[mikesea]

Re: What happened to my impeller?

tHAT KINDA MAKES YA WONDER. i HEARD ABOUT THE SIERRA IMPELLERS DOING THAT 10 YRS AGO.PROBLEM STILL ISNT FIXED RIGHT,AND THEY STILL SELL BAD IMPELLERS. LIKE Said,I wonder how many burned up engines there are because of it. I use omc or yamaha on my engines, its not worth the saving in my book.I save enough doin my own work

 

[ezeke]

Re: What happened to my impeller?

It is a different owner now for Sierra, and there are lots of old impellers around that are still being sold. I would be more interested in the retailer's explanation and comments at this point.

 

[blue fin]

Re: What happened to my impeller?

I had the same problem but come to find out that the reason why it happened was running the motor in a barrel even at iddle there is a lot of fuel that builds up in that tank and everyone knows that fuel and rubber dont take to well to one another it causes the rubber to swell up . i bet that when you took it out the impeller was about a 1/4 bigger than it was when you installed it

 

[i386]

Re: What happened to my impeller?

I had the same problem but come to find out that the reason why it happened was running the motor in a barrel even at iddle there is a lot of fuel that builds up in that tank and everyone knows that fuel and rubber dont take to well to one another it causes the rubber to swell up . i bet that when you took it out the impeller was about a 1/4 bigger than it was when you installed it

We may have a winner here... I don't have a new impeller to compare it too but it was really soft when I took it out. The rubber is a good bit bigger than the brass part. It also reeks of gas even after i washed it with dishwashing liquid.

I have changed out the water several times after I noticed a lot of 2-cycle oil floating in there, but it's been sitting in that water most of the time.

I bet he's right. I'm going to get a valve for the bottom of my "tank" so I can keep it drained when I'm not running it.

 

[mikesea]

Re: What happened to my impeller?

Bluefin,never gave that a thought,I always use the muffs,but the older engines dont use em.That you kind sir

 

[OBJ]

Re: What happened to my impeller?

So does that mean that shops should stop using there test tanks?

I keep mine as clean as possible and add cleaner to the water to help disperse the oils. But I still use it for all my outboard work. Haven't had a problem yet in near 17 years.

 

[i386]

Re: What happened to my impeller?

So does that mean that shops should stop using there test tanks?

Probably not. The shop is going to test it on the tank and give it back to the customer. The customer will probably put it back in the lake.

In my case, it's been sitting in that water off and on for over a month. In addition to draining my tank when I'm not using it, flushing it out with fresh water wouldn't be a bad idea either.

 

[Paul Moir]

Re: What happened to my impeller?

The impeller should be just a few thousands (~ 10) shy of 0.5" thick if you want to confirm your suspicion. Sounds likely right to me though.

 

[OBJ]

Re: What happened to my impeller?

Well, this opens up a can of worms. We tell posters to put there engines in garbage cans full of water all the time if they want to get the engines idle close to norm before putting the rig in the lake or river for final adjustments.

Do we stop the practice or am I over reacting? With all do respect to everyone, I think I need a little more testing and hard facts to make a decision. I could agree with the impeller maybe soaking up some fuel.....if soaked long enough, like a fuel line. But we have to remember that the fuel is diluted by the water. I can't see a few runs in a barrel as being harmful to the impeller for a short period of time.

The therory sounds right.....but....just my opinon.

 

[steelespike]

Re: What happened to my impeller?

I don't see tank testing as a problem just don't leave it sitting in the goo.Motors are tank tested all the time obviously the key is test it and get it out.
I do wonder if the Sierra pumps are more sensitive to
contamination.

 

[i386]

Re: What happened to my impeller?

It measured 9/16" thick. It's already getting harder than when I took it out. I think as the gas continues to evaporate out of it, it'll shrink some.

I think telling folks to run it in a can is fine. The key is to just not let it sit in the "tank" for days on end. Most folks are working to get back on the lake so it's not left sitting anyway. It's the guy bringing an outboard back from death that needs to be cautious.

 

[KYHunter2]

Re: What happened to my impeller?

Another good thread. Also another great reason to install a water pressure guage. Then if the impeller destructs, you'll know it in time, to save your powerhead.

KYHunter