how often do you change your impeller?

Boatist

Rear Admiral
Joined
Apr 22, 2002
Messages
4,552
Re: how often do you change your impeller?

I have changed my OMC Stringer water pump impeller 2 times since new in 1980. Each time the impeller look great. The first time the houseing the impeller runs in was pretty bad, most likely from salt water use at ramps that did not have a wash station. Second time every thing looked great but there to replace the spline short shaft so just made since to change it.

My 1975 15 HP Johnson Outboard has also been repalced twice since new in 1975.
Again the first time it needed it and the aluminum houseing was bad. I replaced with the stainless steel housing. Second time I was in there because I was changing motor from a short 15 inch shaft to a long 20 inch shaft. When your in there just makes since to change water pump and shaft seals. Second time I changed if I had not marked it with a red majic marker I would not have been able to tell the difference.

I never turn over either motor with out water.
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,319
Re: how often do you change your impeller?

Rule of thumb is every 2 years for a high pressure pump.
Every 3 years for a high volume pump.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,417
Re: how often do you change your impeller?

200 hours a year. Gets changed every other year or when I see a drop in a drop in pressure
 

skargo

Banned
Joined
Sep 14, 2008
Messages
4,640
Re: how often do you change your impeller?

I just changed mine in the boat I bought last year. The PO was a great mechanic, except he changed the impeller 10 years ago I just found out. Good thing I changed it.

23456_10150163625795652_554955651_11527435_5325318_n.jpg
 

stubbsboogie

Chief Petty Officer
Joined
Aug 19, 2008
Messages
413
Re: how often do you change your impeller?

Follow the interval for your engine. MIne is every other year.
If there is a question go ahead and change it so that you have the peace of mind. Really cheap insurance.
 

Fireman431

Rear Admiral
Joined
Sep 17, 2007
Messages
4,292
Re: how often do you change your impeller?

I run inboards with engine mounted impellers (Merc 7.4L). I change min every 100 hours. I started to notice that when I take the old ones out, they look just fine. However, you can rip off the vanes easily by hand. I guess that means that although they look OK, doesn't mean they are OK.

I always have the spares onboard...JIC
 

AguaSki

Chief Petty Officer
Joined
Jul 4, 2005
Messages
545
Re: how often do you change your impeller?

I do mine every two years. Since time goes by so fast, it is difficult for me to remember if one or two years have elapsed. To get around this I started changing the impeller on odd numbered years. So, I last changed my impeller in 2009, and will need to do it again in 2011. This system seems to work for me.

Someone also mentioned the shift rod connection on OMC v4's being a PITA. When I first started changing my impeller I agreed with this observation, but I have since learned a little piece of duct tape stuffed inside a socket, and a 1/4 extension works really well. Now I can disconnect and re-attach the shift rod in a few seconds. My first impeller job took the better part of a Saturday morning. Now I can do the job in under an hour, and most of that time is spent getting tools out and putting them away.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
Re: how often do you change your impeller?

I have a document that I created on my computer that lists the name and part number of anything I replace on my boat. Alongside this, I note the date it was last replaced.

My impeller gets replaced every 2 years regardless of hours.
 

cougar1985

Lieutenant Junior Grade
Joined
Oct 7, 2005
Messages
1,023
Re: how often do you change your impeller?

I do mine every two years. Since time goes by so fast, it is difficult for me to remember if one or two years have elapsed. To get around this I started changing the impeller on odd numbered years. So, I last changed my impeller in 2009, and will need to do it again in 2011. This system seems to work for me.

Someone also mentioned the shift rod connection on OMC v4's being a PITA. When I first started changing my impeller I agreed with this observation, but I have since learned a little piece of duct tape stuffed inside a socket, and a 1/4 extension works really well. Now I can disconnect and re-attach the shift rod in a few seconds. My first impeller job took the better part of a Saturday morning. Now I can do the job in under an hour, and most of that time is spent getting tools out and putting them away.
good idea about the duct tape ,will have to file that one away for future use.been about 7 years since i did nine on the 90 but i check every year and every year its still pliable and like new .one of my other motors hasnt had a impeller change for 71 years!evinrude used a metal impeller back then,lol.wonder why they got away from that ?cost ?if i dont know the history of a outboard i change the impeller as a matter of course.7 plus motors and never stranded ,knock on wood (head).lol!
 

Fishing56

Seaman
Joined
Mar 4, 2010
Messages
60
Re: how often do you change your impeller?

OK, I was worried about my lack of maintenance on my boat. Guess I was lucky. Someone told me I was "Boating on borrowed time". I have a 4.3Lx 1996 model. Here is the impeller and houseing that I took apart that is about 14 years old. The old impeller shows no sign of scarring, wear and is still as flexible as the new impeller I installed.

I am in no way suggesting that anyone avoid doing regular mantaince or service intervals. Just showing my results.

Boat is always garaged, no saltwater, sand or much mud. Oh, by the way it has been started numerous times without muffs for 20-30 seconds to make sure it was going to start at lake.

Just dont try this yourself!

Fishing56
 

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bruceb58

Supreme Mariner
Joined
Mar 5, 2006
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30,454
Re: how often do you change your impeller?

The old impeller shows no sign of scarring, wear and is still as flexible as the new impeller I installed.
Sorry, that old impeller looks BAD! Quite a set in those blades!

Oh, by the way it has been started numerous times without muffs for 20-30 seconds to make sure it was going to start at lake..
That could also be why they are so bent...they got hot.
 

Fishing56

Seaman
Joined
Mar 4, 2010
Messages
60
Re: how often do you change your impeller?

[

QUOTE=bruceb58;2567284]Sorry, that old impeller looks BAD! Quite a set in those blades!

That could also be why they are so bent...they got hot.[/QUOTE]

Thanks, wasn't trying to make any type of point other than point out that my impeller looked much better than the 10 year old impeller in the original post. Plus motor always maintained a normal temp or 165-170, even this year before impeller replacement.

Also makes me think someone needs to start a thread on I/O motor alignment. Don't they recommend every year? Ask me about that.

Fishing56
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
Re: how often do you change your impeller?

Let me guess, you haven't checked your alignment in 14 years either and your coupler is still ok.
 

Fishing56

Seaman
Joined
Mar 4, 2010
Messages
60
Re: how often do you change your impeller?

Let me guess, you haven't checked your alignment in 14 years either and your coupler is still ok.

Well, under advice from all you good guys here, I pulled entire unit. Bellows and coupler and alignment was good (although I was pissed that local Merc dealer wouldn't sell or rent an alignment tool). But now I can boat with peace of mind.

Like I said, I am not trying to give adivice, just relay my experience.

Fishing56
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
Re: how often do you change your impeller?

Please tell me you changed your bellows after 14 years.

Now I am really wonderring...how often do you change your oil?
 

StevenT

Petty Officer 1st Class
Joined
Mar 9, 2009
Messages
230
Re: how often do you change your impeller?

I wait till the temp gauge reads max and the oil pressure gauge says 0. I replace the engine and impeller at the same time. :)
 

stylesabu

Master Chief Petty Officer
Joined
Aug 2, 2009
Messages
849
Re: how often do you change your impeller?

must be nice to have money,stevenT. I guess your saying when it overheats you replace it.
 
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