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Does anyone have a recommended service schedule for raw water impellers. I know a lot depends on the water you are in salt/fresh debris or mostly clean. the last time i changed mine i had 262 hrs on it and it looked like new. vanes were very flexible with no signs of any cracking or stiffness.
I am thinking of extending my service to 400 hrs, any thoughts on this would be appreciated.

Thanks

Bill
 

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Generally, changing them once a year is a good idea. They're not all that expensive.
 

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Discussion Starter #3
I seem to have the most expensive one out there at $73.00 dollars, Yanmar 4jh2e. I know, i sound like a tight %&^#.

Bill
 

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My Johnson 810 impeller on my Yanmar 2GM20F lasted 5 years. I checked the manual and it failed at about the recommended running hours.
 

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The only reason I say that you should probably change the impeller out every year is that if the impeller is run dry at all, it will generally "age" much more quickly and become brittle with the heat caused by running dry. This tends to leave it more vulnerable to breaking off vanes and can cause you serious problems by blocking the cooling system. Also, many impellers will take a set when sitting in the same position for extended periods of time... which also makes them more prone to losing vanes.

BTW, if you've had to run the engine dry for any reason, it is probably a good idea to change the impeller as soon as possible for the reason I mentioned above.

If you're careful about removing them, you can always set the old impeller aside for use as an emergency spare. :)
 

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Impeller hours

Hello,

I don't know what the service recommendation is. I check mine when the boat is hauled. The one in the pic was in the boat when I bought it. So it's been in the pump since at least 2006 and 150 hours. Considering how the PO treated the boat, I would think the impeller is much older.



Anyway, after running marine antifreeze through the raw water, I pulled the cover off the impeller and took a good look. I could see that the rubber was starting to crack. I pulled the impeller and I'll install a new one in the spring.



Barry
 

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I just replace mine. I ran the engine for a few minutes with the seac0ck closed. It was a great excuse to have a mechanic look over the whole engine, and to give me a diesel engine lesson. The impeller looked like new. I replaced it anyway and kept the old one for a spare. Note that you need to get a spare gasket (mine are paper and are destroyed at time of removal) or you won't be able to use that old, usable impeller.

It was also a good time to swap out the antifreeze, which turnd out to be a bit watery. This may be the boat's first winter north of Georgia. Also it had "green" antifreeze, but Perkins engines like "blue" apparently.
 

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100 hours or 12 months, whichever comes first. Running it past the 12 month timeframe is risky. It will fail when you need it most. THey are not expensive and it is easy to do. Just make it part of your oil change maintenance. No big deal.

- CD
 

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I change mine once a year.

I hate supprises, they come at the worst time.

I say when I change the damn thing not the engine.

I throw the old one away and buy a new spare and gaskets just incase.

I have an outboard and cannot even imagine hauling it aboard and pulling the lower end to change it.

Right after the new year it comes apart and gets s full tune up regard less of run time. It always starts on the second pull when cold and the first when warm.

I do a couple of dozen engines in January from my little one to up to the new v-6s for my motorcycle clients.
 

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impellar

I have changed my impellars about every 3 years and they always looked just like the new one I replaced it with. But for some reason I just keep on doing it.
 

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Cheap Insurance

As others do, I replace mine once a season (about 6 months). I put about 50 h on the motor each year. I put a new one in in the spring just before launch. Their cheap compared to a tow or a damaged engine.

DrB
 

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Stay away from blue impellers

Try the Globe #075. Defender has them for $34.
I fell for all the nice spec’s that are out there about the blue Globe impellers, but what a fraud. It didn’t last more that 40 hours. Once I friend told me I should stay away from these but I didn’t listen. Know it’s my turn to alert other. I almost fried my engine. I even threw away the other one I bought for replacement. For your safety, stay with the original Yanmar black impellers.
 

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100 hours or 12 months, whichever comes first. Running it past the 12 month timeframe is risky. It will fail when you need it most. THey are not expensive and it is easy to do. Just make it part of your oil change maintenance. No big deal.

- CD

Exactly correct. On the other hand, trying to back-wash the bits of a broken impellor vane out of a heat exchanger can be a serious PITA.

FWIW...
 

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I fell for all the nice spec’s that are out there about the blue Globe impellers, but what a fraud. It didn’t last more that 40 hours. Once I friend told me I should stay away from these but I didn’t listen. Know it’s my turn to alert other. I almost fried my engine. I even threw away the other one I bought for replacement. For your safety, stay with the original Yanmar black impellers.
Bingo!!!! LOTS of bad luck with Globe and lots of others with failures too...

Just a heads up..

I've tried the Globe impellers but found them very problematic. Below are some quotes and photos from another forum. My failures were the center hub spinning free of the blue impeller. This was a tough one to trouble shoot as it looked fine. The next one the tolerances were off ever so slightly and she would not "prime".


Images courtesy P. Shed

P. Shed said:
I was removing the sea water impeller from a M25 this morning . I do it each fall after haul out. To my surprise the impeller was cracked on every vane. This impeller was new this spring. The one I took out was a rubber type and was still like new but was old so changed it out . This is a # 815 . I would say there are only 35 hours on this impeller.


I will be taking it back tomorrow. Also going back to rubber type (black)

Sorry the pics are not the best
Images courtesy Bottomscraper:
Bottomscraper said:
I have been using the Globe Blue Run-Dry™ Impellers for years and I have been very happy with them. I usually remove them at the end of the season and they look almost new with a little discoloration. This year every single blade was cracked. I did notice that this year the center appears to be plastic rather than metal like the older ones. Here is a picture of the impeller I removed today after 1 season (about 120 hrs). It has never run dry.

It appears that they have changed materials and that these impellers are now junk. I guess I will be going back to the black ones also. Too bad they had a good product. I was considering using their motor mounts but I think I will look elsewhere.
And another:

Ken J. said:
I left a dock, must have sucked a bunch of EG up while warming the engine/untieing lines. Noticed the temp was running 10° hotter than normal, stopped in the middle of the bay (no wind) to investigate. Pulled a significant plug of EG out of the strainer/intake. Reprimed the the pump and restarted the engine. Water flow out the back was not normal. Shut down again and pulled the impeller apart. The pictures show the condition of the Globe impeller. It was less than 3 months old, never run dry. It probably ran 20-25 minutes at less than full water flow and never saw temps above 170°. Not buying the 15 minutes run dry.




Just an FYI that the Globe impellers are NOT all they are CRACKED up to be..:D

I replace yearly... Engines are 15k my impeller is $16.00 or about the price of a 12 pack of decent beer..;)
 

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I'm in the change once a year camp and always keep a couple of the old ones on board just in case. Just seems to make sense, and as Maine says they are not all that expensive.

Does anyone have any experience with those quick change Speedseal impellor covers ? I figure their greatest advantage is that they use a much better, as in reusuable, gasket than those damn paper things.
 

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They also make changing the impeller a lot easier, especially if the impeller is in a difficult location, since you don't have to remove all four screws.
I'm in the change once a year camp and always keep a couple of the old ones on board just in case. Just seems to make sense, and as Maine says they are not all that expensive.

Does anyone have any experience with those quick change Speedseal impellor covers ? I figure their greatest advantage is that they use a much better, as in reusuable, gasket than those damn paper things.
 

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SD,
Reality is , I guess that it would be simple to modify a standard impellor cover to be as easily removeable but you are still stuck with the crappy paper gasket. Thats why I reckon its the gasket and the gasket housing design that makes this thing look the goods.
 

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I change mine yearly and keep the spares. I've yet to see one so bad that I trashed it. I do it more as a PM move than having the impeller go south at the worst possible time.

Some folks pull the plate off a couple times a year for a look-see but I don't think you can get a good look at the impeller condition that way, and by the time you get it out you might as well replace it.

I've yet to replace the cam though.
 

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I change mine every 300 hours or 3 years which ever comes first. since I usually put around 100 hours per year it works out pretty good. I used to change every year (100 hrs ) but decided that its just a waste of money, but if it gives you some peace of mind to change every year it may be worth it to you.

Mitch
 
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