Spare raw water pump?

[Bruce K]

I have a spare water pump">raw water pump for my engines, should I leave the neoprene impeller in the pump or maybe vacume packed attached to the pump? It would be much easier to leave it in the pump, maybe smear coated with silicone grease. Any ideas?

[Simi 60]

I took mine out and left sitting in box with pump.
5 minutes to put back in.

[mike d.]

Do not put it in the pump ! It will take the set of the cam in the pump ! This will weaken the pull of water ! Put it in a plastic bag with the gasket Also if the 1 you pull out looks to be ok, keep it as a spare back up !!!

[Jim Cate]

the manufacturers don't seem to worry about the impeller taking a set... why should you?

The new Johnson pump I just bought came with impeller installed, had been on the shelf for a while at the retailer's, some time at the wholesalers, some time in transit from the factory...works fine!

Jim

[billknny]

A smear of silicone grease is a good thing, since the pump will start up dry.

Worrying about the blades "taking a set" is a theoretical one. Even if true, it would only affect the few blades that are actually touching the cam.

I keep spare water pumps for both engine and genset because it is a lot easier to swap the whole pump than to change the impeller in situ in my setup.

I keep them fully assembled, they work.

[a64pilot]

Mine has the impeller in it, like Jim’s it came that way, I left it in there.
Of course that is not my only spare impeller.
Most people who store their boats over the winter do not remove the impeller, I never have for outboards. I had an OLD mercury 10 HP that sat in the barn for probably at least 10 years that pumped water fine.
I have wondered about the shelf life though, if it went into an airplane it would be 5 years.
Do they get hard when they get old, or soften up, or what?

[Bruce K]

Emailed the distributor and they replyed "It is best practice to remove the impeller from the pump. Upon reinstating the impeller it is best to use some impeller lubricant"

[Jim Cate]

Originally Posted by Bruce K

Emailed the distributor and they replyed "It is best practice to remove the impeller from the pump. Upon reinstating the impeller it is best to use some impeller lubricant"

Bruce, if this is such good practice, why do they package, ship, store and sell them with the impeller installed?

Jim

[Simi 60]

Originally Posted by Jim Cate

Bruce, if this is such good practice, why do they package, ship, store and sell them with the impeller installed?

Jim

Because they want the impellers to fail so you buy a new one?

[Jim Cate]

Originally Posted by Simi 60

Because they want the impellers to fail so you buy a new one?

OOohhh noooo, that couldn't possibly be... could it??

On the other hand, I've had spare impellers that died quickly after installation, ones that had been in storage for a couple of years. Rubber stuff does age in the box and on the shelf.

Mine are routinely replaced at 900-1000 hours. Just did one that had over 1100 hours. One vane had the beginnings of a crack at its base, the rest looked quite good. I was kinda surprised!

Jim

[Bruce K]

Originally Posted by Bruce K

Emailed the distributor and they replyed "It is best practice to remove the impeller from the pump. Upon reinstating the impeller it is best to use some impeller lubricant"

Hi Jim; Just reporting what they said! Due to my inbuilt momentum, as the impeller is in the pump at present, it will probably stay there, at least until I open the locker its in!!!!!!!

[EmeraldCoastSailor]

Very interesting timing on this post as last weekend I was going to ask same question.
Instead I took the impellers out of my two spares putting them in a ziplock baggie which is inside a larger ziplock that also contains the spare pump. Yes I have installed multiple pumps that came with impeller already installed so I don't think it is that big of a deal but perhaps this is an ounce of prevention situation. I even labeled the ready stand-by pump "no impeller" via sharpie and masking tape to make it doesn't get installed without impeller insertion.

[S/V Alchemy]

Originally Posted by mike d.

Do not put it in the pump ! It will take the set of the cam in the pump ! This will weaken the pull of water ! Put it in a plastic bag with the gasket Also if the 1 you pull out looks to be ok, keep it as a spare back up !!!

^^^This. Impeller in package, or ziploc bagged, and pump greased up, all bolts ready and paper gasket and rubber ring bagged separately. Label with date packed and note in log what (dry) place you stow it.

[ranger58sb]

Originally Posted by Jim Cate

On the other hand, I've had spare impellers that died quickly after installation, ones that had been in storage for a couple of years. Rubber stuff does age in the box and on the shelf.

We have routinely been told to use our spare impellers first when we do replacements, and then buy new impellers for the spares pile... specifically because of that reason.

-Chris