Etec impeller

[BogMonster]

So, the Etec is five years old in October, and spring/summer is approaching.

Suppose I'd better think about changing the water pump impeller that I was supposed to do this time last year

The reality is that due to other commitments I may or may not find the time to do it before the start of boating season, but I still want to use the boat occasionally. The impeller is clearly supposed to last 300hrs or 3 years as that is the service interval.

So, what are real-world experiences of how long the impeller lasts (time_ with limited non commercial use? Engine has about 120hrs from new, more or less. Pumps fine (or did when I last used it, which was about April or May). A chap here with a dive boat with some old Mariners on it told me a few years ago that he'd never changed his impellers and that was at least 10 years.

It is one of those jobs that if it goes well, shouldn't take too long, but if stuff breaks it will be a pain (and yes I know the longer I leave it the more likely that is).

Thoughts?

[Bushrider]

On my seagoing RIB with an 250 ETEC I change the impeller according manufacturer recommendation . Safety first .
On another boat here in Ukraine which I use for river cruising only with an F100 Yamaha I replaced the impeller in 2007 or 2008 and installed a water pressure kit .
As long the pressure does not drop I am not touching the impeller ..

This is just my PERSONAL opinion !

[Chris]

Originally Posted by BogMonster

So, the Etec is five years old in October, and spring/summer is approaching.

Suppose I'd better think about changing the water pump impeller that I was supposed to do this time last year

The reality is that due to other commitments I may or may not find the time to do it before the start of boating season, but I still want to use the boat occasionally. The impeller is clearly supposed to last 300hrs or 3 years as that is the service interval.

So, what are real-world experiences of how long the impeller lasts (time_ with limited non commercial use? Engine has about 120hrs from new, more or less. Pumps fine (or did when I last used it, which was about April or May). A chap here with a dive boat with some old Mariners on it told me a few years ago that he'd never changed his impellers and that was at least 10 years.

It is one of those jobs that if it goes well, shouldn't take too long, but if stuff breaks it will be a pain (and yes I know the longer I leave it the more likely that is).

Thoughts?

Obviously changing it would be the safest option especially where you boat... !

If you want to risk using it and it then fails you will get an over temp warning and the engine will protect itself although you might be looking at a few miles with your auxiliary...

One thing to make sure is if you are going to leave it I would undo the 5 x L/U bolts one by one, grease them and re-fit. It pays to do this early on in the engines life to avoid seized bolts.

[1eyedjim]

I have a mixed view on this.

Personally I change yearly as last thing I want is to be stuck with a hot engine for a £15 impeller and an hour of my time. Plus it gives me chance to change the gear oil and check other bits out at the same time.

That said on my Bayliner I hadn’t changed the impeller in 2 years due to getting married and finding time to get it lifted out the water and that was still working fine.

On my dad’s boat it hadn’t been changed in 4 years but had done about 6 hours max in that time but the engine was getting hot before being lifted and the impeller had some blades set in the place it was left so wasn’t pumping effectively.

To me being left is potentially just as bad as being used

[jyasaki]

Originally Posted by BogMonster

So, what are real-world experiences of how long the impeller lasts (time_ with limited non commercial use?

Probably not going to find much data on this. Assuming you're running out away from help, an impeller failure is pretty much catastrophic, which is why people replace them before they fail; hence you don't end up with any "how long do they last" data.

Some people replace them every year, some every couple of years, a few run them five years or more. Engine hours is not the best way to gauge their anticipated life, as sitting idle in the yard exposed to temperature swings may be worse for them than running (the vanes, being rubber or a synthetic analog, take a set after a while, and constant exposure to environmental factors can make them brittle.)

Personally, I try and replace mine every couple of years. If it goes 3, I don't worry too much but keep a closer eye on the telltale and head temp.

jky

[Daibheid]

I'd at least open it up and inspect it every 3 years purely to ensure the leg can still be got off. After that much effort ,given the cost, it makes no sense not to replace the impeller. I'm sure your leg is ok at just five years old but I wouldn't underestimate what seawater can do to seize outboard legs in place. Most agents will try sell you the whole pump kit but an impeller alone is less than half the cost and the gaskets etc are reusable if care is used opening the pump.

I've spent months literally trying to get the leg off an engine that hadn't had an impeller in years and if you've ever tried drilling out a broken stainless stud in an aluminium leg you'd pledge body parts to avoid a repeat!

FYI hours are not much of a guide, the impellers harden and can crack. I've an example I took from my engine three years after a dealer replacement after relatively low hours. It has two vanes cracked almost all the way through. Imagine one of those chunks of rubber inside the waterways on an engine - if the didn't block the pump water tube first!

[BogMonster]

Well, it's October, so I suppose I'd better think about it again. Thanks for the input above. Just got to find time for it now! I haven't even been out in the boat since April...

[Mollers]

It's a pretty easy/inexpensive job, so best done. Changed mine this summer, it was 6yrs old. It was unmarked, but had somewhat lost it's youthful bounce.