How does this impeller look?

[Mark42]

Took the impeller out today because I thought the tell tale looked a little weak lately. But I was surprised that it looks good to me, especially being at least 5 years old. What do you think - replace it or no?

I think some 400 grit wet paper should clean up the superficial corrosion on the pump wall and some minor score/wear marks. Or is there a better way to service the pump?

I noticed some silicone grease looking stuff in the pump, on some of the vanes of the impeller, and in the outlet pipe. Wondering if its silicone grease that never washed out? Or just remains of some unfortunate jelly fish?

Thanks!

Mark

 

[cambosoup99]

Re: How does this impeller look?

doesn't look bad to me but since you have it apart might as well get a new one in there. I would clean off that corrosion as best you can. If you know someone with a sandblaster, have them blast it and powder-coat it. it'll help with corrosion. that's what i did with mine.

also if you get the kit, it'll come with new cover i think, at least mine did if your kit is the same fk1069 i think.

 

[92rslt1]

Re: How does this impeller look?

Its out.. replace it. 5 years is a stretch for a piece of rubber.

 

[bman1bpm]

Re: How does this impeller look?

I agree with the other two, its out, why not replace it?

 

[SweeperForce]

Re: How does this impeller look?

I got to agree with everyone. I bought a whole kit for around $75 It came with everything, gaskets, alum plates, key, impeller. The only thing it didn't have are the screws. I replace mine every year as a "waking up" process. It cheaper the buying a new motor. Good luck.

Tom

 

[Mark42]

Re: How does this impeller look?

I have an impeller on order and it will be installed. I was just surprised at how good a condition the impeller was in. Not ripped, not missing chunks, and the trailing ends do not show much wear at all. Goes against everything I have read about impellers being worn out after two to three seasons.

 

[roscoe]

Re: How does this impeller look?

It may not be disintegrating yet, but it has a slight set, and is old.

Doesn't really matter what it looks like, just how it performs.

 

[Mark42]

Re: How does this impeller look?

While waiting for the new impeller, I took the time to wire brush (stainless steel brush) all the bolts that hold the gear case on and the water pump together. Cleaned the pump body, wet sanded the drive shaft to remove some superficial rust (thought that shaft was stainless???) , and cleaned up all the water passages in the gear case.

I found out the gaskets I have are not for the right water pump (grrrrr) so will either order the correct gasket, or just pick up some gasket material at the auto parts store and and cut my own.

Seems parts for these Force outboards are getting more scarce every season.

 

[nathanhooper]

Re: How does this impeller look?

"stainless" steel is really a misnomer. It should be called "stainresistant" steel. And even at that it just depends on the manufacturing process from start to finish. Where I work we use a lot of stainless steel enclosures to house electronics. We have a lot of chemicals to treat our water. We had a new cabinet come in and in the process of less than 6 months it had rusted to the point that it looked like it had been sitting there for 100 or so years. They had just forgot to do a part of the manufacturing process and it caused this blip.

Long story short, stainless steel will rust.

 

[bman1bpm]

Re: How does this impeller look?

I think it's not how the impeller looks it's the material. they are made of a hard but flexible rubber. It's designed to flex at high speed to provide more flow. as it ages the rubber gets harder and is more prone to cracking chipping or breaking. it may be fine still but its easy to change and it'll kill your day on the water if it fails.

 

[Frank Acampora]

Re: How does this impeller look?

The impeller looks serviceable, and indeed looks rather good for 5 years of use.

However, after doing the work to remove the lower unit and water pump it makes sense (and is cheap insurance at 20 bucks or so) to replace the impeller.

 

[Whitakerla]

Re: How does this impeller look?

It may not be disintegrating yet, but it has a slight set, and is old.

Doesn't really matter what it looks like, just how it performs.

I have run into a similar situation and removed an impeller from a 1990 15 hp Gamefisher (Force). I removed it because the motor isn't pumping any water and expected to see a 'destroyed' impeller, but to my suprise, it looked great, EXCEPT when reading roscoe's comment, he mentioned something about a slight set. What is that exactly? If it means that the fins on the impeller are permenantly bent, then that is exactly what my impeller looks like. Will this effect the pumping of water? Because everything else looks fine, the plate, the key, the housing (except for some minor corrosion as well), and I even put ONLY the lower unit in a bucket with the drive shaft sticking up and attached a drill to the drive shaft on high and water did pump out a little. I expected to see a gieser of water with some pressure, but all I got was a dribble. It did have a little bit of pressure when I plug the hole with my thumb. I plan on replacing the impeller per this thread, but does 'set' have something to do with it?

Also, I'm investigating the water pump because I did overheat the motor this past weekend, and concerned about it's health now. I shut off after being in the water for 3 min. I have managed to restart it, (on first pull) several times, but what steps should I take to make sure I haven't damaged it to the point of 'unreliabilty'. And would like to do a compression test, but clueless as to the process, what hot and cold measurements mean or top and bottom. Any help would be great. Thanks!

 

[92rslt1]

Re: How does this impeller look?

The most important thing is how much pressure the fins are putting against the wall of the pump. They can look good to the eye, but water can still push by the weak fins and defeat the pumping effect of it..

 

[Mark42]

Re: How does this impeller look?

I have run into a similar situation and removed an impeller from a 1990 15 hp Gamefisher (Force). I removed it because the motor isn't pumping any water and expected to see a 'destroyed' impeller, but to my suprise, it looked great, EXCEPT when reading roscoe's comment, he mentioned something about a slight set. What is that exactly? If it means that the fins on the impeller are permenantly bent, then that is exactly what my impeller looks like. Will this effect the pumping of water? Because everything else looks fine, the plate, the key, the housing (except for some minor corrosion as well), and I even put ONLY the lower unit in a bucket with the drive shaft sticking up and attached a drill to the drive shaft on high and water did pump out a little. I expected to see a gieser of water with some pressure, but all I got was a dribble. It did have a little bit of pressure when I plug the hole with my thumb. I plan on replacing the impeller per this thread, but does 'set' have something to do with it?

Also, I'm investigating the water pump because I did overheat the motor this past weekend, and concerned about it's health now. I shut off after being in the water for 3 min. I have managed to restart it, (on first pull) several times, but what steps should I take to make sure I haven't damaged it to the point of 'unreliabilty'. And would like to do a compression test, but clueless as to the process, what hot and cold measurements mean or top and bottom. Any help would be great. Thanks!

You may be experiencing overheating due to a stuck thermostat. Possibly clogged water passeges The "set" means that the vanes of the impeller are bent back and not springing back to straight. Impellers are larger in diameter than the pump body they fit in, and therefore, the vanes are bent back touching the wall of the pump body. After a year or two, when removed, they tend to keep a slight bend to the vanes.

Usually a spent impeller is shreaded looking. So much of the tip is missing that the vanes stand out straight.

The most important thing is how much pressure the fins are putting against the wall of the pump. They can look good to the eye, but water can still push by the weak fins and defeat the pumping effect of it..

Actually, the impeller is only touching the pump wall at idle speeds. The impeller is off center in the pump body (by 1/8" or so), so as it rotates, the vanes are bent and straightened a little bit on each rotation. When the motor speeds up, the vanes fold all the way back and don't touch the pump body wall at all! The pump switches from being a simple displacement pump at idle, to a vacuum pump at high speed.

BTW, pump bodies have a small hole in them so that when the leg is dropped into the water, water can fill the pump as air escapes out the little hole (1/32" diameter or so) in the top of the pump. Seeing as both the in and out of the pump are in the bottom, the air bleed is needed to let the pump fill with water and be primed. So it is well worth the time to drop the leg into the water, let it set a minute or two until all the air has escaped out that tiny hole and the pump fills with water. Otherwise, the pump is running dry, and that is the worst thing you can do to the pump.

In the photo below, the air bleed can be seen at about the 10:00 position relative to the drive shaft hole. The pump body is upside down in the photo.