Be Wary (Maybe) of Stay Cool Pumps Impellers

[Bleemus]

And back to impellers . . .

[a64pilot]

Originally Posted by sailorboy1

Maybe people would get better life out of their sw impellers if they stopped messing with them so much.

I don’t get it, how do you “mess” with one?
In four years I have replaced three, first one cause I had no idea how old it was, second due to hours, the third cause it was obvious water flow was down.
I did try a Globe dry run, and think it’s a good impeller, I believe cheaper than a “Yanmar” one which I don’t think is made by Yanmar, just a rebranded Jabsco?
Either way they are ridiculously priced for what they are. I know I’m in the Bahamas, but I paid $98 bucks for one.

[sailorboy1]

Originally Posted by a64pilot

In four years I have replaced three, first one cause I had no idea how old it was, second due to hours, the third cause it was obvious water flow was down.
.

I 9 years and 2 boats, I've replaced 1. And it looked fine other than the damage I did to it removing it.

[stnick]

Impellers are CHEEP compaired to the cost and inconvience of a engine over heating and stopping !
Weather you like black rubber or blue poly Just change the things on a schedule ! Its part of boat care and ownership ! More fun than doing teak !?!

[Hobie_ind]

Originally Posted by daletournier

One thing I absolutely hate about my boat is the postion of the raw water pump (what were they thinking) and the lack of access I have to it. Not sure I could do it at sea.... Grrrrrrrr.

You've got a Yanmar 4JHTE don't you? Do you use Yanmar impellers and their puller?

If you don't you might find this helpful. We had a similar issue with our Yanmar on our Amel. it was the only item on the boat with really poor access! Then when I was buying some spare impellers in St Martin the mechanic asked if I wanted the Yanmar brand impeller or the generic brand for $x cheaper. When I said the generic, he commented I must have great access to the pump, to which I responded 'NO'. He then went in the back and grabbed a Yanmar puller and impeller. The Yanmar impellers are threaded on the front so that the puller can be threaded onto the impeller with a center bolt that just pushes it off the shaft. I never went back!
Coupled with using a zip tie around the impeller blades to get it started for installation and the whole process became a 5-10 minute job.

See the photos below for a better understanding.

Cheers,
Mark

[sailorboy1]

I got one of those pullers

I wish it would have fit!

[a64pilot]

I have good access, and the factory “Yanmar” impellers for a 4JHE are not threaded, although I think it a good idea.

[NoTies]

Nothing quite like slamming a particular product in the thread title then going on to say you don't know how it happened. No mention of lubing the blades and ends. If I was Stay Cool I would be a bit pissed with this uninformed slander.

[a64pilot]

Well lubing the blades isn’t necessary in my opinion on an impeller that is under the water line and therefore full of water before it ever turns.

However I concede your point, it does seem unusual though that if I had a blockage that may have led to failure, it was never noticed and self clearing, but after Gord brought it up, I conceded it as a possibility, cause it is.

I have another stay cool impeller, perhaps I’ll give it another go after I install the strainer

[Thumbs Up]

I have been running STAY COOL brand impellers on my Volvo md 2030's for a few years now. They seem better than the volvo brand ones that I had before. I think that impellers should have a "use by" date. The older they are the stiffer they feel.

[a64pilot]

I changed the thread and included “Maybe”, cause the possibility of mine being old or a self clearing clog does exist.
In the aircraft world all rubber components do have a cure date I think it’s called, the date the rubber was cured, and 60 months is the date of expiration I believe, although I may be remembering a Military rule and not the FAA one.
Of course almost all engines are flying around with seals way more than 60 months old, which makes one wonder how much does age play into it?
My 4JHE Yanmar is 30 yrs old, with all original seals, and doesn’t ever weep, much less leak anywhere.

[NoTies]

Originally Posted by a64pilot

Well lubing the blades isn’t necessary in my opinion on an impeller that is under the water line and therefore full of water before it ever turns.

Sort of makes you wonder why just about everyone else in the world recommends lubing a new impeller and a new lube sachet is so often included with a new impeller kit. The lube isn't just about reducing first start up friction.

[Jim Cate]

The lube isn't just about reducing first start up friction.

So, what do you think the other functions are? The glycerin that is included with the Johnson and Jabsco impellers that I buy surely does not last very long.

Jim

[NoTies]

It's not about what I think it's about what is fact, which is sorely missing from some posts. The lube helps prevent damage to the blades during installation, temporarily softens the rubber to allow more flex in the blades (rather than yanking hard blades tight with a zip tie like some do) and helps to provide a 100% seal on start up to allow for any air entrapment to pass. But then again all the rubber impeller manufacturers might be wrong.

[a64pilot]

Originally Posted by NoTies

Sort of makes you wonder why just about everyone else in the world recommends lubing a new impeller and a new lube sachet is so often included with a new impeller kit. The lube isn't just about reducing first start up friction.

Doesn’t come with a stay cool impeller
But then neither did an O ring.
In truth I don’t remember using a lube, I will sometimes use some dish soap to make installation easier, but any lube is gone almost instantly.
For some installations, like some generators where the pump is above waterline, the lube may be somewhat critical, but my pump is just below waterline so it’s full of water before I start the engine.

The replacement Yanmar branded impeller, that I know is old, but don’t know how old, didn’t come with any lube either, and none was used, and it’s working fine. I ran it several hours, and then removed looking for old impeller bits.

Yanmar impeller left, 9 blades .142” thick
Stay Cool right, 12 blades, .093 thick

Don’t know the significance if any from having more, but thinner blades