Impeller/Water Pump Replacement Often?

Seems like I'm constantly seeing where boat owners are changing out their impellers and/or water pumps on their outboards like every year or two. I have a 1980 model 25 HP Mercury tiller steer and I've had it since the middle '90s and I don't recall ever having the impeller nor the water pump replaced! It seems to pump water out of the hole nicely.

Should I replace both the impeller and water pump even if they seem to be working flawlessly? Is it very difficult to change them out? How much does it usually cost to have it done?

Thanks everyone for your replies.

Do you use it in muddy, sandy water or salt water?

If not - just always make sure it is pumping and you should be OK

I change them every 2 years on in the salt - but we go 100 miles offshore and do not want to get stuck out there

In a lake - what is the worst case scenario - you limp home on your TM

Now if I was running rivers - I would be more worried

Last month I got my first tin, a 14' grumman deep-v with a 1989 mercury 9.9hp motor.

The seller wasn't the original owner and I don't know the service history of the motor or where it was run. (Although I'm almost positive it didn't see any salt water.)

I'm planning to purchase an "impeller kit" and attempt to replace it myself, just for peace of mind. The impeller kits come with gaskets and all the other bits that can wear out. The pump body itself should be re-usable.

F4T,

I would suggest you go ahead and change it out, if nothing else than for peace of mind. I'm not sure about Mercs, but my Johnson OB was quite easy. The hardest part is making sure everything is lined back up when you put it back together. I change mine every 3 years, and even though the impeller looks like new, I know I'm not taking a risk of it going out and burning the engine up. The kit should be about 25-30 dollars; much cheaper than a new powerhead or blown engine. Get a good service manual, I recommend the factory ones, and learn about your outboard. It will definitely pay for itself in the long run.

Skidz

I replace mine every other year.Mercs are no harder than Johnson & Evinrude outboards

call me lucky.....or stupid (probably "stupid" :lol but I've owned many outboards, and changed the impeller once in one of them.

Example: I bought a Johnson 9.9 in 2000, and sold it last yr, and never changed the impeller/pump. Guess it depends on where ya run your boat.
I NEVER hit ground/bottom with it once, and paint looked new on skeg bottom. :wink:

wow i can truthfully say i have never known one to last that long . you must never use it .i change mine every three years

My FW boat's impeller is well over 20 years old

And I use it lots - real lots

more then 3-5 times each week

I change mine every other year just to be safe
my outboard would run 15K to replace it 225hpdi yamaha and I run the tidal river and get into some skinny water
piece of mind is priceless

Impellers should be inspected at least every two years, more often if run in less than perfect conditions. The question you have to ask yourself, specially those running non-replaceable two strokes, is how much is an impeller vs. a smoked powerhead? What's it worth to you? You can live on luck a long time or you can change it out often and know you have good parts that will probably bring you back to the dock each and every time. I buy and sell alot of engines and will only release an engine after that engine has been fully serviced. Some or most of these engines that I purchase are running and running just fine but I never know what has been changed or when until I go completely through them. I always ask myself if I would be willing to send my son out with whatever engine I am getting ready to sell. The answer is always an easy one!

I ran a 1972 Evinrude 25 horse for over 10 years and never changed the impeller, I didn't even know it had one. I only ran in very clear lakes though, Ouachita, Beaver, Hamilton in Arkansas. That "Rude started everytime and ran good so all I ever did was change the lower unit oil maybe twice and put a set of plugs in it. That being said, probably would be a good idea to change it ever couple of years.

I've never changed the impeller on my 04 60 merc 2s since I bought it new. Have a good stream of water out the hole, but have read on numerous boards where its the right thing to do. Is there a good how to on doing this, winter time is coming and would be a good time to do it.

i change mine every year, sometimes twice a year. but my motor can, will, and does pump mud through it hahaha :mrgreen:

my last impeller lasted 1 year.the one before that lasted 6 years. :?

So, if water is coming out of the hole then my impeller is working properly and isn't broken. Correct?

fish4thriLLs said:

So, if water is coming out of the hole then my impeller is working properly and isn't broken. Correct?

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if the stream of water is a good solid steady stream, then yes, you can assume the impeller is working properly, you don't have any overheating alarms, etc., The lower unit on my 60 has no nicks, scrapes, etc., nor does the prop, so I have never hit bottom, etc., and been lucky not to have hit any submerged objects. Guess I'm following the "if it ain't broke, don't fix it" theory. [-o<

fish4thriLLs said:

So, if water is coming out of the hole then my impeller is working properly and isn't broken. Correct?

Click to expand...

Well, my impeller had cracks in it and still pumped fine. So it could be on the verge of failure and still appear to be working fine. As stated before, its good to replace every 2-3 years for peace of mind.

I'm with Pappy on this one, every 2 years if it needs it or not. You don't drive your truck until it overheats then check to see if the cooling system is up to snuff, you maintain it and it will last you a LONG time. When they do go bad, they do it at the worst time possible and usually cause damage, its not worth the risk. Some of the newer motors are using High Volume vs the old High Pressure impellers, they last longer but they still recommend no more than 3 years between changes.

I have a 2006 Princecraft Holiday DLX with a 2006 Mercury 50HP Bigfoot 4 stroke EFI and use it only in fresh water and my brother-in-law works for Merc and his recommendation to me was replace every 3 years. It costs between $40 and $75 for the kit. Youtube has lots of videos on how to replace it. It is not hard to do. Cheap insurance so that it doesn't go bad if it does your engine could overheat and cause other big $ problems.

are there any good "how to's" out there? I'm somewhat mechanically inclined, but never have done an impeller job before. any leads would be appreciated along with a good source for parts needed to get it done w/o having to wait on more parts.