Dead in the water.

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

Simi 60

Guru
Joined
Jul 1, 2016
Messages
5,482
Location
Australia
Vessel Make
Milkraft 60 converted timber prawn trawler
21 hours into a 24 hour passage and I notice black dust coming off raw water cooling pump belt.
Shut down, wipe clean,visually check pump and all appears ok.
Belt seemed slightly loose so gave it some crank and we are underway again.

Checked 20 minutes later and more dust so an alignment issue but it all seemed to be running straight.
Checked again later and the belt has the wobbles and there were clicking noises - bearings are shot in pump.

No spare so figured no option but to plug on and hopefully get to our destination before the pump went terminal.
Tense couple of hours with one eye watching the pump with ER camera and temp gauge with other but we dropped anchor at 11pm after a full 24 hours.

No water leaks but now the pulley was visually askew.

Next morning move boat to a better position as we'll be out of action for a few days and after that 500 metre move the pump is now leaking.
Shut down sea cock, remove pump and google madly.

I can get a new pump - jabsco 7420-1001air freighted from the US for $700 aud
Jabsco direct in Oz are $1300.
I call a local marine engineer and they'll be $1000 for new and $700 for rebuild with 2 day turnaround on a rebuild.
Parts will cost me several hundred alone and even then a bearing replacement may be out of my skill set with limited facilities onboard.

Pump is on this afternoons ferry back to the mainland for rebuild and am contemplating a backup plan for if/when it happens again.

B.O.A.T.
Bring out another thousand.
 
Back up plan.

Buy another pump from the US for $700
Or
Come up with a way to jury rig a 240v deck wash pump into the circuit?
 
I have rigged washdown pump to engine for cooling. Worked fine at very low power setting.

On long trips I usually carry a complete sea water pump for my main engine.
 
Good thing you were paying attention to your equipment! Nice catch and save.
 
Back up plan.

Buy another pump from the US for $700
Or
Come up with a way to jury rig a 240v deck wash pump into the circuit?

Nicely handled. I would probably get a spare pump given your location and the type of cruising you are doing.
 
The PO left me with a spare starter and a spare coolant pump. I bought an identical spare alternator. Don't have a spare raw water pump.
 
With a single engine in remote cruising locations, a spare raw water pump, spare impellers, spare fresh water (coolant) pump, thermostat(s), belts, antifreeze, rescue tape, starter and alternator would be in my spares.

Ted
 
Hope you will find your way to solve your issue.
May the shot bearing be caused by an alignment issue or was it the main failure that shot the belt?


L.
 
Last edited:
"I bought an identical spare alternator."

Install it , when it is operational , carry the existing unit as the spare.
 
Back up plan for me was to have a spare onboard. I had plenty of impellers, but have a friend that is a diesel mechanic. He went over the engine with a fine tooth comb before my trip. He is the one who suggested I carry a spare. I didn't want to spend the money but I did. I'm glad I had it even though it went unused. I did replace the impeller though.
 
Major rebuild kit available for $500US here:
Jabsco 7420-1001 Parts List
and here: Jabsco 7420-1001 Pump
The whole pump here for $500: Jabsco 7420-1001 Self-Priming Universal Pump
And a bunch more places. If the shaft is undamaged, bearings and seals can be found at a good bearing supply. Bring the old ones.
Also Fisheries Supply in Seattle has the pump and has free shipping over $99 but Australia probably doesn't count.


Thanks
Turns out the mob I found in the US were out of stock and a week or 3 before new arrived and your link is about $50 cheaper as well.

As stated, new here was just over $1000 and as it turns out it would be the new model ending in a 0004 which meant shaft modification as the shaft is longer adding to costs again.

Full rebuild is essentualy new but as you pointed out parts are ridiculously priced as is labour here.
Saying that, full rebuild here was almost half the price of new as the new one needed me to pay extra to have the shaft modified and my bits removed from old and refitted to new.(no hex key or woodruff key on pulley so must be heat and press fit)


I did know about being able to match seals and bearings but here would have required ferry back to mainland and car rental for me to do it which would have cancelled out any saving in this instance.
 
Last edited:
Unbloody believable.

12 mths to the day and the bearing is showing signs of dying.
Fine black rubber like powder under the water weep slot.
No signs of water or rust stains but she's on her way out I guess.
Pretty piss poor considering we only did about 350 hours this year.

New one of these will hopefully be here before ours gives up so I'll be able to source non jabsco bearings and seals from a bearing shop for the old one and investigate self repair.

https://bigblueoceanmarine.com/cumm...7420-0004-7420-0101-northern-lights-25-14801/

Beauty of this one is direct swap, tails and pulley already on.
 
Yes, definitely rebuild the old pump and keep it as a spare.

I have replaced two raw water pumps. Both from seal failures, and I had both rebuilt by the local JD dealer. About $300 for rebuild (new pump $850), Johnson gear driven pump. I suspect muddy water has contributed to the failures. I have one rebuilt and one new raw water pump on board as spares, plus additional spare impellers. I regard a raw water pump as a critical spare.
 
Last edited:
Yeah, I got hit with $700 about 350 hours of use ago.
New one is on the way from the states and I'll leave the 350 hour one in until it gets a lot worse like last time, who knows, it might be signs of fail but fail might be another 350 hours away.
 
Hmm, something is causing premature pump failure if you only managed 350 hours. I'd be looking for a contributing factor here like misalignment or a failing bearing that's causing a slight wobble in the pump. The pump failures could be a symptom.

Are all the other bearings and pulleys running true? Are all the pulley bearings good? I've seen an out of true main pulley destroy several alternators before being discovered.The misalignment only showed up in one position. Test the alignment in several spots on the pulleys.
 
I think you were on to something before, use an electric pump. Some cars are using them now and many cars have electric recirculation pumps that run after shutdown (Mercedes, is one) and they are very reliable. I would toss that Jabsco crap. $1000 - complete nonsense and basically, thievery.

Or, use a water pump like the one on the front of your engine that circulates the coolant. They are not good at priming but if you are creative...? Also, I have a pump that circulates my hydronic system, it runs and runs and it is 12v, likes hot water too. No idea if its self-priming.

When my electric fuel pump failed I bought a generic pump from Summit Racing, it was 1/10th of the price of an Onan pump and it works a treat. I will never have a boat that needs salt water to cool, ever again!

By the way, 24 knots? Did you manage to keep her pointed forward?
 
I think you were on to something before, use an electric pump. Some cars are using them now and many cars have electric recirculation pumps that run after shutdown (Mercedes, is one) and they are very reliable. I would toss that Jabsco crap. $1000 - complete nonsense and basically, thievery.

Or, use a water pump like the one on the front of your engine that circulates the coolant. They are not good at priming but if you are creative...? Also, I have a pump that circulates my hydronic system, it runs and runs and it is 12v, likes hot water too. No idea if its self-priming.

When my electric fuel pump failed I bought a generic pump from Summit Racing, it was 1/10th of the price of an Onan pump and it works a treat. I will never have a boat that needs salt water to cool, ever again!

By the way, 24 knots? Did you manage to keep her pointed forward?

+1

I replaced an impeller pump that cooled hydraulics with an 120 vac electric Grunfos. They typically run for years in continuous duty on coolant and if you do have to replace the motor/impeller cartridge there are four screws and you're done.
 
I think you were on to something before, use an electric pump. Some cars are using them now and many cars have electric recirculation pumps that run after shutdown (Mercedes, is one) and they are very reliable. I would toss that Jabsco crap. $1000 - complete nonsense and basically, thievery.
!

By the way, 24 knots? Did you manage to keep her pointed forward?

Oh i agree but it needs to pump out some water, 200 litres a minute at 1500 are the jabsco specs and it is mission critical so I would prefer basic and electric that size does not sound basic.

The new one is not jabsco, its a Korean brand of pump that has the pulley and tails included, so quick change.
Apparently jabsco have changed my pump to a longer shaft, to buy it again would be $1300 here, cut the shaft, re machine keyway, add pulley, add tails so probably close to $2000.

Of interest, Tony Athens of seaboard marine uses a Korean manufacturer for his "better" pump for the 6bt so I'd hazard a guess its the same mob that build the one I bought.
 
Hmm, something is causing premature pump failure if you only managed 350 hours. I'd be looking for a contributing factor here like misalignment or a failing bearing that's causing a slight wobble in the pump. The pump failures could be a symptom.

Are all the other bearings and pulleys running true? Are all the pulley bearings good? I've seen an out of true main pulley destroy several alternators before being discovered.The misalignment only showed up in one position. Test the alignment in several spots on the pulleys.
Its basically a new engine so I doubt its an engine issue
The pump doesn't have the wobbles yet and hasn't failed yet, it just had some rubber come out which I cleaned out/away.
After several hours today, there is no sign of any rubber, wobble or leaking.
 
Hmm, something is causing premature pump failure if you only managed 350 hours. I'd be looking for a contributing factor here like misalignment or a failing bearing that's causing a slight wobble in the pump. The pump failures could be a symptom.

Are all the other bearings and pulleys running true? Are all the pulley bearings good? I've seen an out of true main pulley destroy several alternators before being discovered.The misalignment only showed up in one position. Test the alignment in several spots on the pulleys.

X2. An engine being new is not an excluder. A continually failing heavy duty part is usually a symptom of something else.

Nix on the electric raw water pump idea as well. You want something that pumps proportional to engine speed. You'd have to find a pump that moves the same amount of water all the time as is now delivered at WOT. Not to mention it adding another level of complication.
 
X2. An engine being new is not an excluder. A continually failing heavy duty part is usually a symptom of something else.
.

Well I don't know how long the previous rebuild lasted for but I would suggest it was a while and it hasn't failed yet so continually failing is a long bow to draw.
 
Back
Top Bottom