Not happy with the generic "change your impeller" suggestion

[777funk]

Not to vent but I notice here and elsewhere it's pretty commonplace to see the suggestion of "change your impeller" every time someone buys a used motor. I understand the need for new impellers but after spending an hour trying to get the lower unit splines to go back into position in the motor, this has been a pretty frustrating bout. Especially so knowing that the impeller that came out looked to be in good shape (picture attached).

Perhaps a better suggestion would be, beware that the impeller is unknown and always check for a water stream when the engine is up to temp.

Ok I guess that is a bit of a vent. But in this case trying to get this thing back in has been a bear and I have a sore back and lower unit that won't go into place. I don't think I'll pull a lower unit again for a check up. I'll just use the usual 'pee stream' test to be sure the water pump is pumping. My dad recommended leaving it if it's working and I should have listened to him. Sometimes if it aint broke, diving in to fix it ain't always a good idea.

 

[Bondo]

Not to vent but I notice here and elsewhere it's pretty commonplace to see the suggestion of "change your impeller" every time someone buys a used motor. I understand the need for new impellers but after spending an hour trying to get the lower unit splines to go back into position in the motor, this has been a pretty frustrating bout. Especially so knowing that the impeller that came out looked to be in good shape (picture attached).

Perhaps a better suggestion would be, beware that the impeller is unknown and always check for a water stream when the engine is up to temp.

Ok I guess that is a bit of a vent. But in this case trying to get this thing back in has been a bear and I have a sore back and lower unit that won't go into place. I don't think I'll pull a lower unit again for a check up. I'll just use the usual 'pee stream' test to be sure the water pump is pumping. My dad recommended leaving it if it's working and I should have listened to him. Sometimes if it aint broke, diving in to fix it ain't always a good idea.

Ayuh,.... That impeller looks pretty worn,... It's supposed to be a bi-annual event,...

Learn how to drop, 'n reinstall yer lower unit, so's it won't be so bad, the more often ya do it,.....

 

[sjbs]

Have someone rock the flywheel as you push the lower unit up and it will slide right in.

 

[777funk]

Have someone rock the flywheel as you push the lower unit up and it will slide right in.

I hope so. It's been such a fight. It's not all that heavy to carry it across the shop but the 125 Lower Unit feels like 200 lbs when you're trying to align and lift at the same time. It'd be a lot easier with 2 or 3 guys instead of one. I'll have to pull the boat cover and try again with one of my kids rocking the flywheel back and forth.

Bondo, is that well worn? I'm new to changing these so I don't know what I'm looking at. My dad has never changed one and never had an overheat as far as we know on fishing boats that he's put 20-30 hours on per summer for 20 years. His motors have always run well. I'll probably use mine even less than he does. Surely I shouldn't change the impeller every 10 hours, should I? Is there a recommended change interval? Hopefully changing it once in a while makes it easier for next time... at this point, I don't know if I want to do this again. Might pay to have it done... and I've done LOTS of mechanical work over the years on cars, trucks, small engines etc. I don't take things in.

 

[GA_Boater]

Age kills more impellers than overuse. If a motor is used often, the impeller remains soft and pliable. When not used so much, they get hard and brittle. The only way to tell is drop the lower and look. While you have it down change it They are a cheap part and considered a consumable maintenance item. When they fail, a 10 or 15 dollar part can cost you a lot more.

The change interval is every other year for most motors or hours, depending which come first. I use a floor jack and chunk of wood to hold it roughly in place while I align the splines, shift shaft and water tube. The more I do it, the easier it gets.

 

[777funk]

Well the pain and suffering are over Had the flywheel barely rocked back and forth and it fed right into there. Without that, I don't think it would have gone in. I tried different rotations of the prop in gear and no go no matter what. I was avoiding turning the flywheel because the boat was covered and untying everything and removing the support was a lot of work. But that's the only way it was gonna happen. Thanks for the tip!

 

[robert graham]

Just a suggestion to help....remove the prop before dropping/installing lower unit....makes it lighter and easier to handle...and you need to inspect prop shaft/seals/splines/etc. anyway...

 

[Nordin]

Well I always check the impeller on a unknown or new to me engine. Remember an OB engine can pump water when you start it and then during the ride stop pumping.
In a couple of seconds you ruin the engine and have to put alot of money in it.
Normal interval of changing impeller is 3-5 years and a impeller is very cheap comparing an engine rebuild.

I also use a floor jack as GA_Boater suggest and then rocking the flywheel back and forward.
I have change impellers on many lager OB and never have to give up.

 

[gm280]

I don't know how you are setup and trying to do your water pump service, but wouldn't a little jack under the foot help install it as you used one hand to rock the flywheel? I mean there are ways to do things that help make it easier... JMHO! As far as recommending so many folks that buy used OBs that come on here to first change their water pump impellor, it is a very wise idea for sure. How do you seriously know how the seller cared for the engine that YOU are buying? It isn't that big a problem to change the impellor, and it sure beats boating along and frying or locking up your new-to-you toy! If changing a simple impellor presents this much problems for you, take your engine to a boat shop next time and open your wallet....WIDE!

 

[HotTommy]

My experience is that replacing the lower unit was like many of the other tasks I did on my motor last year. It was much harder while I was in the middle of the job and the end was uncertain, than it was when it was done and I was telling others about it. Your experience seems about par for the course to me.

 

[coolbri70]

he said he just replaced it

 

[Stachi]

Have someone rock the flywheel as you push the lower unit up and it will slide right in.

It is easier to put the lower unit into gear...forward or reverse, doesn't matter...and turn the prop to align splines.....also, the higher you raise your outboard , the easier it will be to do.

 

[jerryjerry05]

Went to look at an outboard.
The owner stated it can be seen running.
Get there and look the boat over,
looks great.
Ask about the impeller and the guy says it works fine.
Ask about starting and the guy whips out a key and starts it right up.
Starts quick and purrrrs.
I didn't mention that he didn't turn the water on cause he didn't have a hose hooked up.

You NEVER know what's been done to a motor unless your the last one to own it.

An impeller can work for 20 years. But the idea of changing is a safety issue.
What happens when your dads motor overheats when your 3-4 mi. from the ramp?

The pic shows an impeller that's been used. Not wore out but well used.
If an impeller sets for a couple of years without moving, the vanes become set and won't function as well.
It will probably still work but how well?

And the very best reason I change my impeller every 2 years is my wife.

If I was to break down with her on board? I would NEVER hear the end of it.
And she wouldn't step foot in there again until there was a new motor hanging off the back.

 

[jerryjerry05]

Oh yea.
I put it in gear and when lifting the drive to reinstall, I pull up on the blade of the prop.
If it's a bugger I get a piece of 2x4 about the right length and use it for a support.

Had a guy call, said he couldn't get his lower back on.

He said if I cold get it back on he'd pay $100 and give me a complete 1987/125.

Took all of 4-5 seconds. It just slid right in.
Sold the 125 for 450$ and took the wife out to dinner on the 100$

He was a little P/O'd

 

[HotTommy]

jerry,
As with many things, the guy didn't pay you for your effort. He paid you for your knowledge. That's where the money is.

 

[Jiggz]

I can perfectly relate with you when trying to re-install the LU. I have serious lower back pains and trying to shove the LU into the splines by myself is just absolute pain. So what I did is use two threaded studs screwed on each side. Raise in the LU through the two threaded studs just up to the edge of the crank shaft splines and thread in the nuts to hold it in place. Remember you do not need to be all the way up there yet nor do you have to be aligned already. This is just to put the LU up and hold it up there.

Now slowly thread in nuts on each studs and slowly raise the LU. If I feel a little resistance I will move either the flywheel or engage the prop and move the prop to align the splines. As soon as I know I am fully aligned on all three, i.e., shift rod hole, spline hole and water tube, I'll start replacing in the mounting bolts and bolt it all the way through except obviously for the last two. Remove the threaded studs and replace the remaining two mounting bolts. Voila! It's a little bit slow process but it is way less painful.

As mentioned, it is easier if you raise the motor in its vertical position (so as not to work bending down or down on your knees), which you can do easily by putting or placing up the front jack stand in its hide or not use position so the trailer tongue is on the ground while its rear end is up in the air.

 

[Boatdoc58]

I have a strong 24 yr old son that I pay to do that kind of stuff.:joyous: He snatches outdrives off like they are nothing !!
We keep track of our customer's service and when it hits two years, we recommend replacing the impeller/water pump kit. The last customer that told me his was pumping fine had a real short weekend and ended up paying almost 5K to replace his V8...... overheated, burnt flappers out, injested water from wakes while he was dead in the water, let it cool down, hit the key and bent everything inside.
An impeller is MUCH easier to do.