Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 12-05-2011, 14:04   #1
Registered User

Join Date: Jul 2006
Location: caribbean winter, Durango,CO summer
Boat: Nordhavn 5740
Posts: 455
Images: 4
When Do You Change Your Impeller ?

After changing the generator impeller the other day, and removing the broken pieces from the heat exchanger, I realized I had little idea as to when to change my generator or main engine impellers.

If one doesn't put many hours on their engine I guess seasonally is OK. That's not my case however. When I do pull an impeller for inspection I replace it if it is starting the fall apart but if it looks OK I am guessing as to how much longer it will last.

So, any words of advice?

Thanks
__________________
Bahamas this winter.
gbanker is offline   Reply With Quote
Old 12-05-2011, 14:28   #2
TEE
Registered User

Join Date: Mar 2010
Posts: 139
Re: When do you change your impeller?

I change mine every season. I would guess that changing one every 500 hours would be about right. The westerbeke scheduled maintenance suggests 500 hours as a mark to check or replace. Personally, I don't believe in checking an impeller and then putting it back in because pulling it out and installing it in my opinion stresses the rubber and can lead to breakage.
http://www.westerbeke.com/aboutus/FAQ.aspx#40
TEE is offline   Reply With Quote
Old 12-05-2011, 15:15   #3
Moderator Emeritus
 
Hudson Force's Avatar

Cruisers Forum Supporter

Join Date: Nov 2008
Location: Lived aboard & cruised for 45 years,- now on a chair in my walk-in closet.
Boat: Morgan OI 413 1973 - Aythya
Posts: 8,453
Images: 1
Re: When do you change your impeller?

I've been averaging about 500hrs/year on my Yanmar 4JH3E for the last ten years and I've had no issues with changing my impeller one a year until recently when I found this impeller not turning because the metallic inner hub had degraded.

I'm more concerned now with the quality of the impellers that I purchase. I've had none of this type of problem with the Johnson & OMC impellers that I used before.
__________________
Take care and joy, Aythya crew
Hudson Force is offline   Reply With Quote
Old 12-05-2011, 16:20   #4
CF Adviser
 
Bash's Avatar

Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
Re: When Do You Change Your Impeller ?

I change mine every other year.

It's a fairly easy system: on odd-numbered years I service the engine myself, but leave the impeller alone. On even-numbered years I have a mechanic service the engine, and I have him change impellers and belts.

The benefit here is that I keep in touch with my engine but that it regularly gets a professional once-over. And this way I leave the impeller for him, which saves on a lot of cursing.
__________________
cruising is entirely about showing up--in boat shoes.
Bash is offline   Reply With Quote
Old 12-05-2011, 16:31   #5
Registered User
 
sabray's Avatar

Join Date: Aug 2008
Location: Wash DC
Boat: PETERSON 44
Posts: 3,165
Once a year. That way I remember the tricks and where it is any longer and I forget how I did it. Sadly I may need to advance the schedule not because of impellar failure but memory loss. I'm An idiot though and use expensive oil. The old impeller goes in a spares bucket.
sabray is offline   Reply With Quote
Old 12-05-2011, 16:36   #6
Registered User

Join Date: May 2009
Location: Vancouver, Wash.
Boat: no longer on my Cabo Rico 38 Sanderling
Posts: 1,810
Send a message via MSN to John A
Re: When Do You Change Your Impeller ?

Take along a spare or two for when stuff happens.
John A is offline   Reply With Quote
Old 12-05-2011, 16:47   #7
Registered User
 
Ziggy's Avatar

Join Date: Apr 2008
Location: U.S., Northeast
Boat: Currently boatless
Posts: 1,643
Images: 2
Re: When do you change your impeller?

Quote:
Originally Posted by CaptForce View Post
I found this impeller not turning because the metallic inner hub had degraded.
I'm more concerned now with the quality of the impellers that I purchase. I've had none of this type of problem with the Johnson & OMC impellers that I used before.
I think it's a fairly common failure mode. I had a Johnson impeller fail this way twice. I now replace the impeller every year, regardless of its appearance.
__________________
... He knows the chart is not the sea.
-- Philip Booth, Chart 1203
Ziggy is offline   Reply With Quote
Old 12-05-2011, 17:47   #8
Registered User
 
Capt Phil's Avatar

Join Date: Jun 2010
Location: Gig Harbor, WA
Boat: Prior boats: Transpac 49; DeFever 54
Posts: 2,874
Re: When Do You Change Your Impeller ?

I'm with John A on this one... always keep a couple of spares in inventory for both your main and gen set. They are cheap and when they go they can severely restrict water flow in your heat exchanger or your pump itself. Like everything else they fail under the worst possible circumstances. If I saw my water temp go up even 5 degrees, i would change out the impeller at the first opportunity. Hard to see failure in the vanes many times so pull and replace with a new one every time. Capt Phil
Capt Phil is offline   Reply With Quote
Old 12-05-2011, 18:13   #9
Registered User

Join Date: May 2009
Location: Vancouver, Wash.
Boat: no longer on my Cabo Rico 38 Sanderling
Posts: 1,810
Send a message via MSN to John A
Re: When Do You Change Your Impeller ?

Things that have occured to my impeller pump while underway:
Laid the boat over in sand/mud and damaged the impeller when it was sucked into the pump
seen a pump that had sucked a jellyfish into the impeller pump
had blades disappear
barnacles on the water intake line inside of the screen causing pump to reun dry.

I ignored the 500 hour thing and checked the condition before beginning a long passage.
One time, while underway, off the south coast of DR., I had to stop and repace the impeller blades.
I jumped on deck as I heard that dreaded DRUM. DRUM, DRUM sound.
He passed so close that my boat did a 90* turn in his prop wash, Then he got on the VHF and laughed his a** off.
John A is offline   Reply With Quote
Old 12-05-2011, 18:21   #10
Moderator Emeritus
 
Pblais's Avatar

Join Date: Mar 2003
Location: Hayes, VA
Boat: Gozzard 36
Posts: 8,700
Images: 15
Send a message via Skype™ to Pblais
Re: When Do You Change Your Impeller ?

If you change the impeller make sure you got the seal. In a pinch, chart paper will work as a seal. I always save the old impeller as a spare. It may be used but usually not failed. It's easier to change an impeller that ain't broke at the dock than one that is at sea. You get a good spare to boot.
__________________
Paul Blais
s/v Bright Eyes Gozzard 36
37 15.7 N 76 28.9 W
Pblais is offline   Reply With Quote
Old 12-05-2011, 18:37   #11
cruiser

Join Date: Mar 2011
Location: Santa Catalina Island, Ca. USA
Boat: Power Cruiser: Free Agent
Posts: 164
Re: When Do You Change Your Impeller ?

I change them every year.

A sea strainer is a good investment.
Especially if you are unfortunate enough to have the Mercury Plastic sea pump.

The longer life / run dry impellers seem to not pump as much as the factory stock impellers so I avoid them.
Free Agent is offline   Reply With Quote
Old 12-05-2011, 19:42   #12
Marine Service Provider
 
Maine Sail's Avatar

Join Date: Jan 2007
Location: Maine
Boat: CS-36T - Cupecoy
Posts: 3,197
Re: When do you change your impeller?

Quote:
Originally Posted by CaptForce View Post
I've been averaging about 500hrs/year on my Yanmar 4JH3E for the last ten years and I've had no issues with changing my impeller one a year until recently when I found this impeller not turning because the metallic inner hub had degraded.

I'm more concerned now with the quality of the impellers that I purchase. I've had none of this type of problem with the Johnson & OMC impellers that I used before.
That looks like a Globe Impeller. I have had numerous occasions to see Globe Impellers with spun hubs. I like their concept but the darn things just don't hold up as well as OEM despite likely having a purportedly better compound.

Oh and I change yearly..... To inexpensive not to...
__________________
Marine How To Articles
Maine Sail is offline   Reply With Quote
Old 13-05-2011, 15:15   #13
Moderator Emeritus
 
Hudson Force's Avatar

Cruisers Forum Supporter

Join Date: Nov 2008
Location: Lived aboard & cruised for 45 years,- now on a chair in my walk-in closet.
Boat: Morgan OI 413 1973 - Aythya
Posts: 8,453
Images: 1
Re: When do you change your impeller?

Quote:
Originally Posted by Ziggy View Post
I think it's a fairly common failure mode. I had a Johnson impeller fail this way twice. I now replace the impeller every year, regardless of its appearance.
Hey, Ziggy, I agree; however, the outcome in my photo was an occurance when I was in compliance with the yearly impeller replacement. They do not all seem to last a year when you run around 500 hours a year.
__________________
Take care and joy, Aythya crew
Hudson Force is offline   Reply With Quote
Old 14-05-2011, 20:50   #14
Registered User
 
Ziggy's Avatar

Join Date: Apr 2008
Location: U.S., Northeast
Boat: Currently boatless
Posts: 1,643
Images: 2
Re: When do you change your impeller?

Quote:
Originally Posted by CaptForce View Post
They do not all seem to last a year when you run around 500 hours a year.
Right. I typically put on less than 100 hours per year. But I do carry a bunch of spare impellers anyway.
__________________
... He knows the chart is not the sea.
-- Philip Booth, Chart 1203
Ziggy is offline   Reply With Quote
Old 15-05-2011, 06:52   #15
TEE
Registered User

Join Date: Mar 2010
Posts: 139
Re: When do you change your impeller?

Quote:
Originally Posted by Ziggy View Post
Right. I typically put on less than 100 hours per year. But I do carry a bunch of spare impellers anyway.


The problem is not really replacing one if your old one wears out. The problem is the potential for engine shutdown due to overheating when the worn out impeller blows apart and fouls the water flow in the heat exchanger. Then instead of a half hour impeller change, you got a eight hour tear down of the heat exchanger and an impeller change. I think everybody should carry a spare, but have to agree that off brand impellers may not be of the same quality as the manufacturer of the engine.
TEE is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Impeller Question.... gbanker Engines and Propulsion Systems 10 15-04-2011 10:09
Yanmar Impeller Change boeing1 Engines and Propulsion Systems 16 21-02-2011 19:26
Log Impeller sanctuary1 Marine Electronics 12 01-01-2011 12:09
Impeller Lifespan ? boden36 Engines and Propulsion Systems 20 30-08-2010 07:26
Westerbeke Impeller skipmac Engines and Propulsion Systems 15 21-09-2009 08:44

Advertise Here


All times are GMT -7. The time now is 23:21.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.