exfinnsailor
Well-Known Member
Everything seems fine .. Boat is now 18 months old and we have 100 hours on the clock .. Is it time ..
When DO you change an Impeller
- Thread starter exfinnsailor
- Start date
PurpleKate
Well-Known Member
I've just been on the RYA Diesel engine course and the instructor recommended to do every Spring. I've just done mine (boat is 12ths old) and the old one looked perfect so I'm keeping as a spare (clearly labelled as used).
stav
Well-Known Member
Once a season seems to be the recommended and I certainly like to change it in the spring after it has either sat for 5 months (I never seem to get around to taking it out if the boat is ashore) or it has not had much use over the winter. Therefore a better question might be: Who has had an impellor break up and how long had it been in the water pump.
Pye_End
Well-Known Member
Mine looks fine end of year one (under 150 hours), and end of year two, but looks jaded end year 3.
gavin_lacey
Well-Known Member
I had one break on a 2030 after 127hrs, the next one was replaced after 100 and had several cracks. Since then I have stuck to the 100 hrs recommended but they seem in good condition when replaced. Maybe they take less hammer once the case and plates have worn a bit or maybe the warm water helps keep the flexible now as compared with north sea when new.
WindermereColvic
Well-Known Member
Theoreticly every season, but as per previous post, i have just found out that from now in they cost £25, so ill be getting plenty of practice sailing on to the mooring this year!
TheBoatman
Well-Known Member
I find myself stuck between a rock and a hard place on this one!
As an engineer by trade I've always worked on the old maxim of "if it ain't broke don't fix it" but as a yotty and boatman I also realize that at certain times it's best to replace something that "ain't broke"?
Ferinstance, I would replace the freshwater (drinking water) filter every year, I wouldn't replace the diesel filter every year if I'd only done a couple of hundred hours on the engine. I do replace the engine oil & filter every year, but I don't bother with the gearbox oil until about year 3-4.
I take the mast down every 3rd year to re-make the electrical connections, change the nav bulbs and grease the pulleys, but I don't bother to change the cutlass bearings unless they need it!
I think that it's "horses for course's" I.e. whatever you feel is right and good for you, when you're "out there".
Peter.
As an engineer by trade I've always worked on the old maxim of "if it ain't broke don't fix it" but as a yotty and boatman I also realize that at certain times it's best to replace something that "ain't broke"?
Ferinstance, I would replace the freshwater (drinking water) filter every year, I wouldn't replace the diesel filter every year if I'd only done a couple of hundred hours on the engine. I do replace the engine oil & filter every year, but I don't bother with the gearbox oil until about year 3-4.
I take the mast down every 3rd year to re-make the electrical connections, change the nav bulbs and grease the pulleys, but I don't bother to change the cutlass bearings unless they need it!
I think that it's "horses for course's" I.e. whatever you feel is right and good for you, when you're "out there".
Peter.
johnphilip
Well-Known Member
Modern Volvo 20 hp
1st year ,service by agent to preserve warranty- did not see impellor
2nd year impellor had worn ends and a broken blade at end of season
3rd year near disaster, in August started engine, no water from exhaust- impellor had lost 2 blades and another one split
Why such wear and tear? and no we did not run it with the sea cock turned off!
Old boat the impellor was changed religiously but never much wear
1st year ,service by agent to preserve warranty- did not see impellor
2nd year impellor had worn ends and a broken blade at end of season
3rd year near disaster, in August started engine, no water from exhaust- impellor had lost 2 blades and another one split
Why such wear and tear? and no we did not run it with the sea cock turned off!
Old boat the impellor was changed religiously but never much wear
Refueler
Well-Known Member
My boat is in its 10th year of ownership and I've have only seen my impellor twice.
OK engine was swapped about 4 yrs back. The previous 4-99 ran on the same impellor for the 5 - 6 yrs I had the boat, no problem. Engineer fitted the 4-107 in it's place and told me all was good.
Last year I got fed up with the drip of water out of the back of the water pump. So decided it was time to dismantle and replace the seal. It all came apart nicely, impellor looked like it had just come of the shelf - I checked for cracks, splits, any signs of impending doom ... nothing. Having got size for seal - it was all put back while we hunted down a seal locally. Seal was sorted, all apart again, fitted, impellor checked again, bolted up. So this will be year 5 that I know off and I suspect that it was not new when engine was fitted - it was a second-hand cheapie .... 250 quid, it had stood in yard shed for 2 - 3 yrs after being taken out of a Rustler 30 when it started to smoke a little.
When I did the seal - I was not only one who saw the impellor condition - the other guy who is engine 'savvy' also checked it and was of same opinion as me - it aint broke - don't fix it !
Of course there is another matter - that probably to get replacement I would have to have it posted into Latvia from outside. Doubt if I could get such here.
OK engine was swapped about 4 yrs back. The previous 4-99 ran on the same impellor for the 5 - 6 yrs I had the boat, no problem. Engineer fitted the 4-107 in it's place and told me all was good.
Last year I got fed up with the drip of water out of the back of the water pump. So decided it was time to dismantle and replace the seal. It all came apart nicely, impellor looked like it had just come of the shelf - I checked for cracks, splits, any signs of impending doom ... nothing. Having got size for seal - it was all put back while we hunted down a seal locally. Seal was sorted, all apart again, fitted, impellor checked again, bolted up. So this will be year 5 that I know off and I suspect that it was not new when engine was fitted - it was a second-hand cheapie .... 250 quid, it had stood in yard shed for 2 - 3 yrs after being taken out of a Rustler 30 when it started to smoke a little.
When I did the seal - I was not only one who saw the impellor condition - the other guy who is engine 'savvy' also checked it and was of same opinion as me - it aint broke - don't fix it !
Of course there is another matter - that probably to get replacement I would have to have it posted into Latvia from outside. Doubt if I could get such here.
CX54WEK
Well-Known Member
Have had our S23 with KAD32 for 5/6 months now and have gone through 2 impellors already. It was changed as part of a full service when we bought her and then we picked up some crap from the river and broke another running it with no water for a few minutes. Needless to say we now carry a few spares incase we eat another.
doug748
Well-Known Member
Had my last engine 10 years. I looked at the impeller now and again and it seemed fine. I never changed it and the spare went when I sold the engine.
New engine is coming up for 3 years. I think this has prompted me to check it out before I go in the water.
New engine is coming up for 3 years. I think this has prompted me to check it out before I go in the water.
Danny Jo
Well-Known Member
I get the impression that an impellor will run for ages provided it's lubricated by water. A hunch again, but the first few revs before it sucks in water put it under a lot of stress.
When the engineer was commissioning the engine he asked me for a kettle and primed the pump by pouring water in through the raw water filter.
When I take the impellor out for inspection, I put it back with a little Fairy liquid.
When the engineer was commissioning the engine he asked me for a kettle and primed the pump by pouring water in through the raw water filter.
When I take the impellor out for inspection, I put it back with a little Fairy liquid.
Phoenix of Hamble
Well-Known Member
I change my every two years, but do remove it over the winter....
Having had one fail on me at sea, I make an effort to keep an eye on it...
Also carry several spares....
Having had one fail on me at sea, I make an effort to keep an eye on it...
Also carry several spares....
Refueler
Well-Known Member
My boat is moored in a private channel at back of my house and often the water level drops such that I am scraping keels going out. The bottom has lots of reed roots and stuff embedded in and when pushing the boat out - the water strainer gets blocked. I hear the exhaust note go harsh and I stop engine. Clear the strainer ... put back ... start engine again and carry on. It sounds a brutal way to treat my boat - but it's a tank ! I may have to clean strainer 2, 3 or 4 times before I get boat out to deeper water. Impellor has not suffered for this in any way.
I am planning to get a spare replacement to join the other spares I have in a box somewhere that has dissappeared into the boats locker somewhere !!
I am planning to get a spare replacement to join the other spares I have in a box somewhere that has dissappeared into the boats locker somewhere !!
Ariadne
Well-Known Member
Horses for courses, depends on how old/well your engine is.
I change my oil filters every 150hours, secondary diesel filter when the big primary has clogged up with crap 2-3 times and the impeller every spring. Works for me.
Oil in the saildrive...........well I can get about a third out with a small pump, but a full oil change when I get lifted, so every 3 three years at the current spacing.
I change my oil filters every 150hours, secondary diesel filter when the big primary has clogged up with crap 2-3 times and the impeller every spring. Works for me.
Oil in the saildrive...........well I can get about a third out with a small pump, but a full oil change when I get lifted, so every 3 three years at the current spacing.
Two Sheds
Member
It seems to me that impellers may vary in their service lives. Sometimes you get lucky and sometimes you don't. I would be loathe to replace a good impeller for this reason. I check the impeller every season but only replace it if it is not in tip top condition.
TamarMike
Well-Known Member
With my previous boat I had difficulty getting the right size impellor as it seemed to be an obsolete size, whenever I did track one down it was very old stock and often wouldn't last very long before shedding an arm. From this I deduced that the age since manufacture seemed to be as important as how long it had been in the engine.
The problem with a broken impellor is that the broken chunks of rubber can get stuck in the cooling pipes and take a bit of tracking down!
The problem with a broken impellor is that the broken chunks of rubber can get stuck in the cooling pipes and take a bit of tracking down!
brianhumber
Well-Known Member
Re: When DO you change an Impeller - An alternative view
Until I read some other's replies I was not going to reply as I am usually in a minority of one on here in my views with respect to maintenance.
I try not to wait until it breaks before fixing it but I do wait until just before it breaks. So my oil is several years old, filters the same and impeller is now on its 5th season. My water system is cleaned and chlorinated every season however.
Saves me a lot of money and the planet resources and to some peoples surprise my engine has outlasted many others with traditional maintenance and is still on its orignal injectors and pump and up to spec after 21 years.
You must remember a lot of people and authors just repeat what they have read and others have demonstrated before them - they seem to be stuck in the planned maintenance mode and reluctant to teach condition based maintenance which progressive industry has been using for 50 plus years now or perhaps they do not any real expertise in the first place.
However at the end of day everybody has to be in their own individual comfort zone I suppose.
Brian
Until I read some other's replies I was not going to reply as I am usually in a minority of one on here in my views with respect to maintenance.
I try not to wait until it breaks before fixing it but I do wait until just before it breaks. So my oil is several years old, filters the same and impeller is now on its 5th season. My water system is cleaned and chlorinated every season however.
Saves me a lot of money and the planet resources and to some peoples surprise my engine has outlasted many others with traditional maintenance and is still on its orignal injectors and pump and up to spec after 21 years.
You must remember a lot of people and authors just repeat what they have read and others have demonstrated before them - they seem to be stuck in the planned maintenance mode and reluctant to teach condition based maintenance which progressive industry has been using for 50 plus years now or perhaps they do not any real expertise in the first place.
However at the end of day everybody has to be in their own individual comfort zone I suppose.
Brian
neil_s
Well-Known Member
I've found that when the impeller gets a bit old, the vanes seem to become floppy and the pump has trouble getting started. Changing it every 2 years seems to ensure reliable service so thats what I do.
Neil
Neil
Refueler
Well-Known Member
Re: When DO you change an Impeller - An alternative view
Brian - my engine is a lot older than yours ... and I treat it the same way. No problems ... starts on the button, runs like a dream ...
Impellor may be old as the hills - but I pump water like it's Niagara Falls out the exhaust !!
This is when engine is at near flat out ...
This is when engine at idle :
Not bad for an old'n ...
Brian - my engine is a lot older than yours ... and I treat it the same way. No problems ... starts on the button, runs like a dream ...
Impellor may be old as the hills - but I pump water like it's Niagara Falls out the exhaust !!
This is when engine is at near flat out ...
This is when engine at idle :
Not bad for an old'n ...