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NashCraft
06-01-2012, 12:04 PM
Bummer,

First day out for the season and my impeller failed on the way to the gas dock. I was told it would last two years and it was not necessary to replace it. The boat is a year old with 80 hours on it. No more. A new one every season regardless.

I noticed it when the gauges started creeping up and I shut the engine down.

A few questions:

Can impellers fail during the season and while cruising? If so, how would you know?

At what point do the sensor alerts for engine temp, etc.trip?

Do you keep a spare and is it easy to replace? I have an X-25 with a Ilmor engine.

ntidsl
06-01-2012, 12:06 PM
Keep two spares and the wrench you need to change it.

O2BESOHUGE
06-01-2012, 12:19 PM
Mine Has An Alarm That Goes Off If It Gets About 200 Degrees...i Found Out And Heard It The Hard Way Too! Replaced The Impeller And It Stays About 150 Degrees All The Time. About A 15 Minute Fix On The Indmar 351

Huskie05
06-01-2012, 12:28 PM
I keep a spare on board, also change it every spring. Piece of mind. We put about 100 hours on the boat every summer, so its due in MHO.:)

PS195
06-01-2012, 12:47 PM
mine failed when we were out skiing, wife was driving the boat, I got back in the boat after a set and as always check guages. good thing, temp was about 200 and climbing, shut her down immediately, checked impeller first and not one spine was intact. swapped it out in 5 min, took another 15 min to get all the bits from a couple other places where they were trapped in a screen.

mzimme
06-01-2012, 12:49 PM
Welcome to the club. If you boat long enough, this will happen. Be prepared when it does in the future and it'll ruin an hour of your day at most. The good news is, boats generally are equipped with beer as well... so you can make it a "social event" if you had to ;)

BrooksfamX2
06-01-2012, 12:51 PM
I have had them last 5+ years, but always carry a spare and the tools to replace.

O2BESOHUGE
06-01-2012, 01:20 PM
Tip: The Liquid Soap You Use To Get Into Your Good Slalom Ski Is A Good Lube To Slide The New Impeller Into Place. It Worked Great For Me!

ntidsl
06-01-2012, 01:30 PM
it would probaby help break down any oil/gas exitting thru the exhaust too...look bubbles!!!

TNH2oSkier
06-01-2012, 01:41 PM
Install a new impellor every spring before the first outing. It will never be a problem again.

JimN
06-01-2012, 02:16 PM
Bummer,

First day out for the season and my impeller failed on the way to the gas dock. I was told it would last two years and it was not necessary to replace it. The boat is a year old with 80 hours on it. No more. A new one every season regardless.

I noticed it when the gauges started creeping up and I shut the engine down.

A few questions:

Can impellers fail during the season and while cruising? If so, how would you know?

At what point do the sensor alerts for engine temp, etc.trip?

Do you keep a spare and is it easy to replace? I have an X-25 with a Ilmor engine.

The impeller should be removed when the boat is winterized if you plan to use the old one as a spare. They develop 'set', which means they conform to the shape of the housing over time, and won't provide as much pressure when needed. The vanes weaken when they don't generally become stronger over time once they have set.

Impellers can fail when they need to fail, never before.

CCAnderson
06-01-2012, 02:40 PM
IMHO impellors are the weakest link in the cooling system. While they most likely fail at the beginning of the season they can fail at anytime. Always keep a spare on hand in the boat along with the necessary wrench and two flat screwdrivers (used to remove the old one) for when that moment occurs. Is doesn't take long to ruin one if the water supply is cut off by a clogged intake. I once sucked up a plastic bag and did not have a spare impellor. The lake was only three miles long but it took us several hours to make it to the dock. Idle until the temp hit 200, shut down, drink, idle, shut down, drink, repeat. The worst part was the cooler ran dry.

mzimme
06-01-2012, 02:47 PM
IMHO impellors are the weakest link in the cooling system. While they most likely fail at the beginning of the season they can fail at anytime. Always keep a spare on hand in the boat along with the necessary wrench and two flat screwdrivers (used to remove the old one) for when that moment occurs. Is doesn't take long to ruin one if the water supply is cut off by a clogged intake. I once sucked up a plastic bag and did not have a spare impellor. The lake was only three miles long but it took us several hours to make it to the dock. Idle until the temp hit 200, shut down, drink, idle, shut down, drink, repeat. The worst part was the cooler ran dry.

Like I said... "social event"

:D

19_Skier
06-01-2012, 04:48 PM
IMHO impellors are the weakest link in the cooling system. While they most likely fail at the beginning of the season they can fail at anytime. Always keep a spare on hand in the boat along with the necessary wrench and two flat screwdrivers (used to remove the old one) for when that moment occurs. Is doesn't take long to ruin one if the water supply is cut off by a clogged intake. I once sucked up a plastic bag and did not have a spare impellor. The lake was only three miles long but it took us several hours to make it to the dock. Idle until the temp hit 200, shut down, drink, idle, shut down, drink, repeat. The worst part was the cooler ran dry.

So, bring a spare impeller OR lots of cold drinks! :D:D

kskonn
06-01-2012, 05:29 PM
So, bring a spare impeller OR lots of cold drinks! :D:D

Or Both if you really want to be a boy scount.

Jim@BAWS
06-01-2012, 05:41 PM
I have had them last 5+ years, but always carry a spare and the tools to replace.

Maybe in an un opened package new on the shelf!!!

jafo9
06-01-2012, 06:10 PM
The worst part was the cooler ran dry.

i think that is when i would have started to panic. were you able to flag someone down to help refill your cooler?:):)

GoneBoatN
06-01-2012, 06:25 PM
Maybe in an un opened package new on the shelf!!!

Made me chuckle. :uglyhamme

BrooksfamX2
06-01-2012, 07:08 PM
Maybe in an un opened package new on the shelf!!!

not so.......the longest I have had one last is 5 seasons in a Merc I/O but I boat in very clean lake water, no sand or silt to create wear. Maybe its just luck. When I changed the 5 year old one it was still complete and looked good. I changed it cuz I was getting worried about it failing during the 6th season..........I have never had an impeller fail in 30 years of boating, because I change them before they do.

Maybe the MC ones wont last as long....

mikeg205
06-01-2012, 08:07 PM
new impellor every spring....$35ish dollars - pull old one when winterize and spray with 303 put in baggy for spare.

Tools to check impellor and oil cooler - $20 bucks - I inspect the if water has debri - grass and crud floating...

No cooling problems - priceless....

coz
06-01-2012, 08:39 PM
A few questions:

Can impellers fail during the season and while cruising? If so, how would you know?

.

I had one go while pulling a boarder, I heard a sudden change in engine sound (throaty sounding) and immediately checked the temp gauge and it started going up so I shut down, checked the 25 hour old impeller and the fins were intact but the rubber had separated from the spline shaft. So yes, they go while cruising and they don't have to be old. Do like everyone says.....spare.

sand2snow22
06-01-2012, 09:59 PM
Maybe in an un opened package new on the shelf!!!

I changed the original impeller out of a 2006 X-Star with 260 hours on it. 1/2 of every vein was missing, but it was still pumping water :D July would be 8 model years....

charrison327
06-02-2012, 05:00 AM
how long is one good for, by this, i mean in the package unopened. buddy of mine found one when he was cleaning up in his garage and doesn't have a boat anymore. it is the same one that my boat uses but was wondering if i should trust it or not. he said that he thinks it's about 10 years old. it doesn't appear to be hard or brittle. just wondering what some of you guys with way more knowledge think??????????

Thrall
06-02-2012, 01:03 PM
I've used impellers for 2 seasons with no problems and I've pulled one after one short season and it was missing pieces.
New one every year for me.
I have so many extra, used, impellers I toss them out as pary favors to people with Indmar powered boats!:D

JohnE
06-02-2012, 03:54 PM
The consensus here is to change every year. I did that faithfully for a long time. I'm jsut beginning the 4th season with my current impeller. I always have a spare. I'll probably change the current one soon just because this thread reminded me of it.

Ironhorse
06-04-2012, 09:11 AM
Does anyone know if the dealer does this during the winterization? I have not changed mine and have owned the boat for 3 years.

PS195
06-04-2012, 09:18 AM
mine does not but you could ask yours
if its easy to get at, do it yourself, could be one of the easiest maintenance chores

JimN
06-04-2012, 09:29 AM
Does anyone know if the dealer does this during the winterization? I have not changed mine and have owned the boat for 3 years.

Your dealer should have some kind of document that details what they do when winterizing. Personally, I would rather replace it in spring. If your dealer hasn't mentioned the impeller in 3 years, I have to question their practices and motivation. Are they always swamped? Do they act like they're constantly frantic, trying to get everything done? Are they always talking about being under-staffed?

FYI- re: "the dealer"- all dealers are NOT the same. MC has tried to get their dealers to maintain a certain level of training for their techs but the dealers don't seem to want to do what it takes to keep their customers happy. They're letting dealers ruin their reputation and it's time the dealers step up and do their job, IMO. Apologies to the few good dealers I have read about. If they all did what is needed, we wouldn't have many service-related threads here, would we?

BrooksfamX2
06-04-2012, 09:55 AM
........... I'm jsut beginning the 4th season with my current impeller. I always have a spare. ..............

Guess I'm not the only one that gets multiple seasons out of an impeller. I always have a spare in the boat though and the tools required to replace it. Takes about 10 minutes.

Philscbx
06-04-2012, 10:55 AM
I tried to get mine out, but it refused - the boat was needed for out of town guests - so I'll get to it later.
Didn't want to tear it up the hour before going on duty.

What would be nice - if there was a threaded bore before the shaft splines to insert a bolt to jerk on.
Guess I have to invent the wheel again.

A handy spot would be set screw at rear side of body to insert a screw drive to push it out..

BrooksfamX2
06-04-2012, 11:18 AM
I tried to get mine out, but it refused - the boat was needed for out of town guests - so I'll get to it later.
Didn't want to tear it up the hour before going on duty.

What would be nice - if there was a threaded bore before the shaft splines to insert a bolt to jerk on.
Guess I have to invent the wheel again.

A handy spot would be set screw at rear side of body to insert a screw drive to push it out..

There are pullers. I got a used one off amazon for $35. Works great.

ntidsl
06-04-2012, 12:26 PM
Two paint can lid openers...they doubel as bottle openers and impeller removers. Two birds, one stone...keep them in your glove box with your extra impeller and gasket.

Philscbx
06-04-2012, 01:22 PM
There are pullers. I got a used one off amazon for $35. Works great.So the puller grabs the impeller from the bore of it?
Very cool if link is handy.

BrooksfamX2
06-04-2012, 02:36 PM
looks like this........

http://www.google.com/#hl=en&sugexp=eqn%2Ccconf%3D0.95%2Cmin_length%3D2%2Crate_ low%3D0.015%2Crate_high%3D0.015%2Csecond_pass%3Dfa lse&gs_nf=1&cp=15&gs_id=1m&xhr=t&q=impeller+puller&pf=p&sclient=psy-ab&oq=impeller+puller&aq=0&aqi=g2g-K2&aql=f&gs_l=&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=24cf5cb42d7b81b2&biw=1287&bih=756

thatsmrmastercraft
06-04-2012, 04:10 PM
looks like this........

http://www.google.com/#hl=en&sugexp=eqn%2Ccconf%3D0.95%2Cmin_length%3D2%2Crate_ low%3D0.015%2Crate_high%3D0.015%2Csecond_pass%3Dfa lse&gs_nf=1&cp=15&gs_id=1m&xhr=t&q=impeller+puller&pf=p&sclient=psy-ab&oq=impeller+puller&aq=0&aqi=g2g-K2&aql=f&gs_l=&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=24cf5cb42d7b81b2&biw=1287&bih=756

Slick looking puller.

MattsCraft
06-04-2012, 04:22 PM
That sure is one heck of a contraption for something that is simple to remove with a little WD40 and a paint can opener.:rolleyes:

SilviaMan
06-04-2012, 04:33 PM
I always figured if it was coming out a new one was going in... who cares if it gets all messed up on the way out.
cool looking puller none the less.

CruisinGA
06-04-2012, 04:34 PM
not so.......the longest I have had one last is 5 seasons in a Merc I/O but I boat in very clean lake water, no sand or silt to create wear. Maybe its just luck. When I changed the 5 year old one it was still complete and looked good. I changed it cuz I was getting worried about it failing during the 6th season..........I have never had an impeller fail in 30 years of boating, because I change them before they do.

Maybe the MC ones wont last as long....

All the I/O impellers I have seen are much more like outboard impellers, not inboard impellers.

General consensus on my lake is to change outboard impellers every 3 years. Inboard every year. They definitely do not last as long.

BrooksfamX2
06-04-2012, 05:02 PM
That sure is one heck of a contraption for something that is simple to remove with a little WD40 and a paint can opener.:rolleyes:

To each his own..................8p

BrooksfamX2
06-04-2012, 05:05 PM
All the I/O impellers I have seen are much more like outboard impellers, not inboard impellers.

General consensus on my lake is to change outboard impellers every 3 years. Inboard every year. They definitely do not last as long.

Well, as can be seen in this thread, they can last from only a couple months to 3-4 seasons.......do what makes you feel good, but always carry a spare.....;)

sand2snow22
06-04-2012, 07:56 PM
That sure is one heck of a contraption for something that is simple to remove with a little WD40 and a paint can opener.:rolleyes:

I've used the puller and your style. Sometimes one is easier than the other. Really depends on the boat.

CCAnderson
06-05-2012, 09:08 AM
Interesting point about Merc I/O impellors. In the families old I/O, the impellor was rarely changed. Why do they last so much longer than the the impellors in a direct drive? Together we might solve this mystery but we better make sure the coolers are full. It may take awhile.

BrooksfamX2
06-05-2012, 09:20 AM
Interesting point about Merc I/O impellors. In the families old I/O, the impellor was rarely changed. Why do they last so much longer than the the impellors in a direct drive? Together we might solve this mystery but we better make sure the coolers are full. It may take awhile.

Being and ex-I/O guy(25 years), this conversation is just like the ones on the I/O boards. Some folks change every season regardless, others do not. It's the same basic GM motors in a lot of cases, just a different cooling scheme. I had the 5.7 Merc in my Crownline.

I have found that the cleanliness of the water also affects the impeller life. Muddy, silty water wears on them. Also beaching and sucking sand and debris through them takes a toll. We boat in clean mountain lake water, never beach the boat and impellers easily last multiple seasons

JimN
06-05-2012, 09:39 AM
Interesting point about Merc I/O impellors. In the families old I/O, the impellor was rarely changed. Why do they last so much longer than the the impellors in a direct drive? Together we might solve this mystery but we better make sure the coolers are full. It may take awhile.

They last longer because the raw water comes in through the lower unit, not a fitting on the bottom of the hull. Also, this impeller rotates at the engine RPM, not the propshaft RPM. That alone makes a big difference, especially when the pump is run dry.

The same companies make both types of impeller. Don't think for a minute that a Mercruiser impeller will live through being run dry. When the raw water supply is cut off, the complete housing and impeller need to be replaced (if it has the plastic cover) and that can't be done without removing the lower unit on the Alpha One units, 880 and some other models. In addition, the raw water tube will need to be replaced and if left long enough, the bellows and other parts need to go, necessitating removal of teh whole out-drive and sometimes, even the engine. In the case of the Bravo and certain other out-drive models, the raw water pump is mounted on the engine and driven by a pulley. In that case, it's often a helluva lot harder to get to the oil cooler and pump because they're a lot lower in the bilge. If the impeller on one of those goes bad and the system overheats, the exhaust tubes need replacement and that's not a happy time, either.

I really have to wonder why people neglect the impeller as often as they do. It's not that hard to get to on mid-engine models and even on a V-drive, it's not the worst thing in the world. I'm a big guy and I didn't have any problem getting in there, if you don't count all of the time I had to waste removing/replacing all of the stuff people used to leave in their boat's storage compartments when they brought it in for service. I also have to say that it seems pretty lazy for someone not checking the oil cooler at least occasionally. The manual in the late '90s clearly stated, in the pre-boating checklist, that the oil cooler should be checked every single time. They didn't include that so they could use up the ink.

Philscbx
06-06-2012, 12:05 AM
I also have to say that it seems pretty lazy for someone not checking the oil cooler at least occasionally. The manual in the late '90s clearly stated, in the pre-boating checklist, that the oil cooler should be checked every single time. They didn't include that so they could use up the ink.My 04-209 Pre-Launch Inspection - I'm very glad I made a copy of the critical notes from the manual of what to check.

A full service was also performed - Oil/Filter - to full scrub down/buff out.

2 serious situations showed up which would of made being out on the lake a bad day.
Removing the oil cooler lower hose - reaching finger inside - found it plugged with sea weed.
Removed upper hose - Airtank nozzle in hand - blew the wad out.

Currently looking at water intake strainers.
I see this as a high risk of overheating if craft is used by others not watching gauges.
http://farm9.staticflickr.com/8015/7342814618_31ba74a40f_n.jpg
Larger view (http://farm9.staticflickr.com/8015/7342814618_31ba74a40f_b.jpg)

Bilge Pump Inspection - This also was plugged - Entire Bilge was then steam cleaned using orange ZEP to dissolve all the oil film from what I suspect from sloppy oil filter changes.
Tested pump for operation placing it in small bucket of water with a mix of Zep in it to clean it and the hose run.

http://farm8.staticflickr.com/7078/7158470407_2491b1ddca_n.jpg
Larger View. (http://farm8.staticflickr.com/7078/7158470407_2491b1ddca_b.jpg)

Thanks' Jim - will be watching for any tips/suggestions.

CCAnderson
06-06-2012, 10:41 AM
Being and ex-I/O guy(25 years), this conversation is just like the ones on the I/O boards. Some folks change every season regardless, others do not. It's the same basic GM motors in a lot of cases, just a different cooling scheme. I had the 5.7 Merc in my Crownline.

I have found that the cleanliness of the water also affects the impeller life. Muddy, silty water wears on them. Also beaching and sucking sand and debris through them takes a toll. We boat in clean mountain lake water, never beach the boat and impellers easily last multiple seasons

The old maxum only got an impellor change only after it was accidnetally run dry or when we blew the bevel gears and rebuilt the unit. Parts guys have to love those alpha one units. We ran the muddy lakes in Iowa and beached almost every weekend so it certained got a good does of sand and silt. As far as speed goes I thought the gear reduction took place in the botom bevels next to the prop so the impellor should be turning the same RPM as the engine.

Any thoughts on if there is benefit from contstant water submersion becuase the impellor is located below water line at startup? if so I 'm thinking about how to incorporte an anti siphon mechanism in the rwa water intake so that everytime you the boat out the impellor stays in a water. i have to belive that the engineers looked at self priming and rulled them out.

mikeg205
06-06-2012, 11:09 AM
I run in the illinois river and I always inspect the raw water intake and impeller takes jsut a few minutes - the illinois is a muddy river and after rains there is usually extra junk in the water grass etc... considering a sea strainer but read issues regarding those too.

I have 3 outboard motors which indicate changing out the impeller every 50 or so hours as well. Easy on the 30HP a bit more challenging on the 90... lower unit is a bit heavy. my 1959 merc gets one every year if I use it.

bigmac
06-06-2012, 04:05 PM
Currently on my 6th season with the same impeller. I don't have it removed it in the spring, my dealer just pickles the cooling system with -100 PG.

Changing the impeller on a V-drive with Silentmaster muffler is a major PITA.

JimN
06-06-2012, 07:58 PM
The old maxum only got an impellor change only after it was accidnetally run dry or when we blew the bevel gears and rebuilt the unit. Parts guys have to love those alpha one units. We ran the muddy lakes in Iowa and beached almost every weekend so it certained got a good does of sand and silt. As far as speed goes I thought the gear reduction took place in the bottom bevels next to the prop so the impellor should be turning the same RPM as the engine.

Any thoughts on if there is benefit from contstant water submersion becuase the impellor is located below water line at startup? if so I 'm thinking about how to incorporte an anti siphon mechanism in the rwa water intake so that everytime you the boat out the impellor stays in a water. i have to belive that the engineers looked at self priming and rulled them out.

Yeah, you're right about the RPM reduction. I forgot that the pinion gear is down there.