Outboard water pump impeller

[HeaveToo]

How often do you replace your outboard water pump impeller?

How often do you re lubricate your lower unit?

I have heard of some people saying 1 time a year and others saying 1 time every 3 years.  I really didn't run my outboard for that many hours last year and the P/O said that it has recently been done.  Debating on changing mine this spring.

[mikew]

Well it depends- My example- I bought a used 2001 Yamaha 4 HP/ 4 cy. outboard in 2009. It ran well but after several hours the " pee stream
" out the back looked weak. I pulled the lower end and the water pump impeller had a broken fin, which luckily was still was in the pump housing. I replaced it and got a strong flow out the back. So this impeller went for 8 years of light use. But I think that is way too long. I just bought that motor used and it looked as though it was never replaced. In light use as a sailboat aux. , time is the enemy causing more of a "dry rot" to occur cracking the fins. So with light use I change my impeller every 3 years. If the motor had very heavy use, once per year. Keep an eye on the telltale stream every time you run the motor- ( sometimes this small hole gets clogged- carry a piece of wire to clean it first ).
The lower end lube gets changed each fall. When you drain the lube make sure no water has gotten in. Water will change the color of the lube to a milky color. If this mixture stays in the gear housing through the winter, fresh or saltwater can damage your lower bearing surfaces. If water does get in check your drain screw gaskets first, then the lower shaft seals.

Mike  

[Bob23]

Mike's nailed it.
  I got lucky and noticed my impeller wasn't pumping just before I launched last year. I suppose I should change it periodically  but I was operating under "if it works, don't fix it".
  I also change my lower unit lube every fall- it's part of the winterization, even if I've hardly used the motor. Easy, cheap- I bought an inexpensive pump at the local mom and pop boat shop for 12 clams.
Bob23

[hoddinr]

I usually change the oil, foot lube, and impeller once each year.  That may be more frequent than necessary, but it's cheap insurance that the water will pump to cool the engine and the oil will be fresh and keep things lubed.  The dealers tell me one to two years is good practice, but I like to err on the side of caution when it comes to machines, which I basically don't trust.  I have several removed impellers for a Tohatsu 4 that look almost new, if anyone wants them.

Ron

[MacGyver]

At work we change lower unit oil atleast once a year. Impellers, well, wait till it goes out.
At home I plan to change my lower unit oil once a year, (I have a new Tohatsu 6hp Sail Pro) and the impeller I will probably wait as I am always checking the pee stream because I am extremely particular (my wife calls it paranoid....) and watch it constantly.

Mac

[hoddinr]

I picked up my Yamahammer 4 HP today at Star Marine in St. Pete.  Jimmy, the new owner said that the impeller was still good, but that it was still good practice to throw in a new one every other year at least.  He said he gets people that brag about never changing them, and then when they go bad the head, leg and foot of the engines are so corroded together that he can't get them apart without breaking them.  Then the owners have to pay $1000 for the repair or buy a new engine. 

Easier to just get it serviced every year or so.

Ron

[Gerry]

Impeller = every 100 hours (unless you run in sandy or weedy water), then once a year.
Bottom unit lube = once a year.

[kickingbug1]

like mac i watch the stream and given that my merc 4 horse sees little use (it is on a sailboat after all). ill replace it when i see a "weak" stream. he an outboard is like an old man---who would have guessed

[frank]

"weak stream"   :-)

My dad used to say

"I used to be able to pee over my boots...........now I pee all over them"     :-)

[Cats Paw]

On the Subject.
Does any member know of a link or info on changing {HOW TO} the impeller? I have a Tohatsu 3.5
This is something I have never done and would not know where to start.

Thanks in advance.

[Bob23]

I had to change the impeller on my Nissan...I have a repair manual. But I'm sure if you google what you're looking for, you'll find it. It wasn't all that hard but as with anything mechanical, common sense is your best friend.
Bob23

[Jim23]

Cats Paw...Here's a link to a youtube video showing an impeller change out on an 8 HP Tohatsu. I think you'll find the impeller replacement to be pretty simple if you've done any other mechanical work. Removing the shift shaft retaining pin was the toughest part for me. I don't think the impeller had ever been changed on my motor so the pin was locked in pretty tight. After that it was just disassemble-reassemble with no real challenges.

http://www.youtube.com/watch?v=Lh6z2hTrNJg

[HeaveToo]

I just ordered my water pump impeller kit from Defender.  The price was $39.99 and shipping wasn't too bad.  The kit had the gaskets, bolts, shaft key, and impeller.  I am guessing that this isn't a bad deal for that price. 

[ChuckO]

Best Guess - I use my outboard 40 hours max per year and I normally replace an impeller when indicated by a weak 'pee stream'; service the lower unit seasonally.  Have had no problems.

Death to an impeller is starting the motor out of the water as you often see people do with the thought: "Just to make sure it starts - then I shut it down" .. One revolution of the engine is enough to cause damage .... as previously mentioned ... sucking up sand or dirt can also be bad.

ChuckO'
1987 CP16-2
Charleston, SC