Lehman 120 Raw water pump

If you have a Lehman 120, has your original raw water pump drive failed?

If not and you are still running your Jabsco pump I would like to know this also?

If you have changed out to the Johnson Pump,* was your original drive cracked?

If not and you still have it do you want to sell it?

Please include engine hours and approx year of engine as I am trying to determine how common this drive failure is.

Thanks JohnP

When I bought my Albin 4 years ago the first thing I did before I ran the boat was upgrade to the Johnson pump.
The old pump still worked nothing was cracked (3300 hours) and I sold it one e bay in a couple of days.


-- Edited by jleonard on Saturday 5th of February 2011 09:16:29 AM

I've got the Johnson pump after mine 1983 failed at 2100 hours approx.

JohnP wrote:
1. If you have a Lehman 120, has your original raw water pump drive failed?

2. If you have changed out to the Johnson Pump,* was your original drive cracked?

3. If not and you still have it do you want to sell it?

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1.* On the port engine, almost, but not quite.* This was at about 2,500 hours.* The starboard engine was fine.

2.* Yes, that's how we found the port drive was almost shot.

3.* No, we retained the drive and pump off the starboard engine as a spare.*

If you are thinking to try to get a second drive to have as a spare my advice is to forget the Lehman drive and Jabsco pump altogether and convert to a Johnson pump.* The problem is that when the Lehman drive fails you immediately lose your raw water cooling.* The engine will immediately and rapidly overheat and unless you catch it right away before the temperature gets too high, you'll most likely kill the engine--- the head gasket will go pretty quick and the chances are good the head will warp.

Remember, the temperature overheat alarm (if it works at all) will most likely sound to tell you that the engine has just catastrophically overheated and the engine is toast.* That's what alarms are for, right?--- to tell you that the piece of equipment they're monitoring has just failed. * That's why we have a timer at the helm that dings every five minutes to remind us to check the engine instruments--- it's very easy to get distracted on a boat with stuff like whales and the scenery and (up here) looking out for debris in the water.

If you have a single-engine boat, carrying a spare drive is a good idea BUT..... do you want to be down in the engine room doing a major project like changing out the drive, switching pump over to the spare drive, and dealing with the hoses with the boat rocking and rolling in a seaway?

Better, I think, to simply change to a Johnson pump and eliminate the problem once and for all.* If the original pump and drive are okay, keep them as your spare.* You will want to keep the original pump output hose with the Lehman setup, too, since it will be shorter than the one on the Johnson.* Saves you having to cut a new hose or cut down the hose from the Johnson pump.

*

Marin wrote:


Better, I think, to simply change to a Johnson pump and eliminate the problem once and for all.* If the original pump and drive are okay, keep them as your spare.* You will want to keep the original pump output hose with the Lehman setup, too, since it will be shorter than the one on the Johnson.* Saves you having to cut a new hose or cut down the hose from the Johnson pump.

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Marin, Sounds like the Johnson Pump is the logical*solution to this "problem".

There our so many of these engines in service I was wondering if there were a large group of users in the "ignorance is bliss" catagory.

I know a boat on my dock has 8000 hrs on his Lehman and I don't think he knows about the pump drive issue.

At least I know the temp alarm works as it sounded one day after a long run as I was pushing* more than I should have in the East River-they don't call it Hells Gate for nothing.

The temp gauges only read slightly above norm, and I throttled back and cycled in and out of gear, to take the load off. IF the gauges climbed any higher I would have been forced to shut down in strong currents in a very busy place.

Luckly the alarm stopped within a minute or so.

Since then I have made sure all the coolers and heat exchanger are clear.* And more importantly run in a more conservation RPM range.

I know I was lucky because I did not know how sensitive the Lehmans*were to damage by overheating.

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********* JohnP

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-- Edited by JohnP on Sunday 6th of February 2011 09:03:00 AM

" And more importantly run in a more conservation RPM range."


With normal PM it is usual to operate 10-15 minuets at full throttle , every so often to assure proper cooling and engine operation..

IF you have a "cruising prop" (oversized to reduce cruise rpm ) its full bore less 300 RPM, to asses the engine.

JohnP wrote:

There our so many of these engines in service I was wondering if there were a large group of users in the "ignorance is bliss" catagory.

I know a boat on my dock has 8000 hrs on his Lehman and I don't think he knows about the pump drive issue.

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I have no idea how often this inherent weakness in the Lehman drive actually causes a failure.* I assume not all that often since I had never read anything about it on the GB owners forum, where a good many of the forum members have boats powered by FL120s.* On the other hand, I get the impression that a great many of the FL120 owners on the GB forum run the Johnson pump, not the stock setup.*

We did not know about the drive tang problem until our diesel shop pulled the pump and drive for another reason and found the cracking driveshaft.* They had encountered this problem enough in the past to know the cure--- the Johnson pump.* It was when I called American Diesel and talked to Bob directly about the Johnson pump that I learned the history of the Lehman drive that I related earlier.

Bob did not tell me what causes the cracking and I didn't think to ask.* So it may be that inconsistencies in the manufacturing of the driveshaft, or harmonics within the engine, or who knows what influences the longevity of the shaft.* So some shafts may go 14,000 hours with no problems where others might start to crack at a couple thousand hours.

In a twin engine boat it's not a big deal since there's a spare engine .* The big deal is if the operator fails to see immediately the engine temp start to climb and shuts the thing down before any damage is done.

In a single-engine boat I'd be inclined to be more concerned about it.* Since I get the impression that the cracking occurs over time until the tang ultimately fails, perhaps a smart thing to do (if one doesn't want to change to the Johnson pump) is to inspect the drive tang periodically.* Since the Jabsco pump should get a new impeller every x-amount of running time, and the cover plate will need to be replaced or flipped every x-amount of running time, one of these operations may be an ideal time to remove the pump from the drive and have someone who knows what to look for inspect the coupler drive.* If it looks good, keep going until the next inspection.

John P:
If your cooling system was working properly, and if nothing clogged up your salt water intake, you should never get to overheat condition that would fire off your alarm.
Perhaps you had a plastic bag sucked into the intake through hull, restricting water flow, thus causing your engine to overheat. When you took it out of gear you changed the hydro pressure of the water flow on the outside of the hull and it may have been enough to pull the bag off......
You should still verify that your cooling system is working as it is supposed to. Normally, according to Bob Smith, you should be able run your Lehman engine for extended periods at full throttle without it overheating. Bob recommends the full throttle test be applied to our engines regularly to verify it all works as its supposed to. Go full throttle, watch the temp gauge, it may move up a little but should stay close to normal operating temp (180-190).
If not then you have some blockage in the cooling system.
R.

ralphyost wrote:

John P:
If your cooling system was working properly, and if nothing clogged up your salt water intake, you should never get to overheat condition that would fire off your alarm.
Perhaps you had a plastic bag sucked into the intake through hull, restricting water flow, thus causing your engine to overheat. When you took it out of gear you changed the hydro pressure of the water flow on the outside of the hull and it may have been enough to pull the bag off......

Your idea of a temporary blockage could be correct.** The condition has not repeated itself and I do run up to full throttle (2500rpm) for short periods and have not noticed any increase in temp on the gauge.

When I get the Johnson Pump I would be tempted to buy the 1" opposed to the 3/4.

I also make sure to bleed the air out of the petcock on the manifold if I do anything to the freshwater side of the system. Recently I replaced the exhaust outlet elbow.

JohnP

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Changing to a 1" pump is not benefit unless you have a 1" through hull. Check your through hull first. If its 1" then most definitely go to 1" pump.
R.

!" thru hull and sea strainer and hose to pump. Fitting at pump presently adapts to 3/4 pipe thread.** JohnP

Install a 1inch Y style strainer AFTER the rubber impeller pump is a great low cost cruising insurance.

When the pump rubber dies and shreads , its caught in the easily cleaned Y strainer , not somewhere in your engine or heat exchanger.

I went the extra 2 miles and installed a 1 1/2 inch thru hull, strainer, etc. to make sure I had plenty of water available, plus extra room for debris if I ever need it.

If one changes the impeller regularly there won't be a need to cacth impeller parts downstream.

First stop downstream is the engine oil cooler. Approx one foot away.* Pop off the hose and it is easy to feel if any pieces are there. Have not had any break off on this boat yet.

JohnP

Out of interest my Lehman 120 port engine raw water pump is being replaced as we speak, this despite a complete engine rebuild about 3 years ago. Also on the same engine the manifold has also been sent away to be re machined as the end plate was not true and consequently we were loosing fresh water and also some exhaust into the engine room,also the heater exchange has been sent away for an overhaul. Not really very happy as the rebuild was worth $25,000

shrimp wrote:

Out of interest my Lehman 120 port engine raw water pump is being replaced as we speak, this despite a complete engine rebuild about 3 years ago. Also on the same engine the manifold has also been sent away to be re machined as the end plate was not true and consequently we were loosing fresh water and also some exhaust into the engine room,also the heater exchange has been sent away for an overhaul. Not really very happy as the rebuild was worth $25,000

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**********I cannot believe for 25k they did not install the Johnson Pump, you mean they just redid the whole engine and kept the original Jabsco pump and drive?

JohnP

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*"I cannot believe for 25k they did not install the Johnson Pump, you mean they just redid the whole engine and kept the original Jabsco pump and drive"

Why would they change it? What would be the rebuilder's impetus to change it to a different design?
What I can't believe is $25K to rebuild a Lehman 120. That is insane. Sorry. If a major portion involves the R&R then perhaps I could understand it a little.

jleonard wrote:What I can't believe is $25K to rebuild a Lehman 120. That is insane. Sorry. If a major portion involves the R&R then perhaps I could understand it a little.

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I go along with that for sure, particularly if the boat is single-engined.* For $25k you can get rid of the Jurassic Lehman and replace it with a modern, more efficient, smoother, less noisy and less polluting diesel like the 150 hp Lugger N/A straight six.

*

jleonard wrote:

*"I cannot believe for 25k they did not install the Johnson Pump, you mean they just redid the whole engine and kept the original Jabsco pump and drive"

Why would they change it? What would be the rebuilder's impetus to change it to a different design?


A shop commanding this much coin for a rebuilding should have known the apparent weakness in the original pump drive, and at least advised the boat owner of the potential problem.

Impetus- To give the owner a reliable engine.

JohnP

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The rebuild was an insurance claim so I guess their wasn't a lot of incentive to improve but mainly to replace the existing set up. The $25K was broken down into the following, bearing in mind the boat is a twin.
1/ Initial troubleshooting & removal of engine $2,000
2/ Labour/ Reassemble engine, commission etc $3,600
3/ Shipwright $600
4/ Slipping/Crane $1,500
5/ Engine rebuild labour $6,100
6/ Engine Parts $4,800
7/ New Injector pump/labour $2,700
8/ oil/tax etc $3,700

As the engine was out and the labour for removal & installation was covered by the insurance we had the gear box overhauled as well, which cost us an extra $1500 all up. This is the second Lehman we have had rebuilt under insurance, we had the gearbox overhauled on the earlier one as well. Prices were broadly similar.

I'm going to have a look at the boat tomorrow morning so I will ask the mechanics about the Johnson pump. I think that being all the way across the world we don't have the options/prices available to you guys, unfortunately. Remember we have only about 10% of your population with approximately the same land area, not counting Alaska, so we don't have your economies of scale. Still on the upside we have a lot of room to move, which is good.

PS sorry about that silly smiley face I hit the wrong button and can't get rid of the dam thing

"A shop commanding this much coin for a rebuilding should have known the apparent weakness in the original pump drive, and at least advised the boat owner of the potential problem."

I don't agree that they should have known. Not unless they participate in some of these boating forums, or have an MTOA membership, etc.

JohnP wrote:

A shop commanding this much coin for a rebuilding should have known the apparent weakness in the original pump drive, and at least advised the boat owner of the potential problem.

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*

That will depend on the shop and if they have encountered any problems with the Lehman pump drive in the past.* The shop we use has, and so knew all about the Johnson pump and recommended it the moment they saw our drive was failing.* Other shops, even shops with Lehman experience, may not be aware of the problem.* We'd never heard of it even after years on the GB forum until the shop found the problem.* We knew about the option of using the Johnson pump from the GB forum, but we'd never heard about the potential failure of the Lehman drive.


-- Edited by Marin on Thursday 10th of February 2011 03:26:53 PM

How difficult is it to change out the raw water pump to the Johnson pump?* My starboard engine has the Johnson pump, but I am going to replace the port Jabsco with a new Johnson.

Thanks for your wisdom!

Wannabe.* The port engine has the raw water pump toward the center of the boat I believe.

This should be very accessable.

It is pretty easy to change.

Shut the seacock.
Remove the hoses.
Remove 4 bolts and pull off the Jabco pump.
Remove the 3 bolts holding the original pump drive.
Pull the drive out of the front housing, it will have a gear on it.

Install the new Johnson pump with the 3 bolts that held the drive on.
The Johnson should have a new gear on it.
Reconnect the hoses--you may need new longer ones.
Open seacock and go.

Call Bob Smith at American Diesel to get his advice on this.

Save your old drive unit for the Jabsco--Someone on this forum needs it, if it is not broke.* It is a great spare for those with the original setup.

JohnP

"with a new Johnson"

Make it the Big Johnson** ...no really there is one with larger ports.

There is also a tapered pin that you have to put into the oil feed hole for the gear if I remember correctly. That was in the instructions that come with the kit.

I sold my old original pump. It went quickly. At least I was able to recoup a few dollars.

Our original pump failed in 2006 and at the time Atlantic Yacht Basin in Great Bridge, VA replaced it with a new Jabsco. They see lots and lots of these engines and are a very reputable yard yet they didn't know about the design flaw in the adapter. Well of course late in the afternoon in 2009 at the start of a night crossing of the Chesapeake the adapter failed and I had to replace the whole thing while being towed. By incredible luck the tow operator was coming out of Reidville and I got Brian at American Diesel to leave a pump outside so the tow guy could pick it up and bring it to me when he came to tow me. I was able to restart and release the tow but the experience was $600 of waste. I don't really blame AYB for not knowing #%&$ happens.

Wannabe wrote:

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How difficult is it to change out the raw water pump to the Johnson pump?* My starboard engine has the Johnson pump, but I am going to replace the port Jabsco with a new Johnson.

Thanks for your wisdom!

*

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Easy enough that I did it while being towed in a steady chop. Took less then two hours start to finish.

*

shrimp wrote:This is the second Lehman we have had rebuilt under insurance

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Why did insurance pay for two re-builds?

Well, the first time the boat was slipped stern first up a fairly steep slipway,as it turned out the sea water in the exhaust box drained past the riser into the top of the engine cylinders.Other work was being done to the boat so it was about a month before they tried to start the boat, by then the damage was terminal. The second event is still somewhat of a mystery to us, the engine cooked during a short trip , no more than 30 minutes. When my partner heard the engine buzzer sound he shut down the engine, but it appears the damage had been done, one cooked engine.The insurance company was pretty good about it, considering two engines in four years cost them over $50K. Back to the Raw Water Pumps thread....At the moment I am looking at the invoice for the repair of my two raw water pumps on the Lehmans, that were done during the boat's service last week.One pump was leaking a bit and needed looking at, the other I had done on the 'better safe than sorry principle'.I am a bit stunned that the service for the 2 pumps was over $1,400, which does not include removal or refit.I hesitate to ask, does this seem somewhat over the top?

Shrimp wrote:

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'I am a bit stunned that the service for the 2 pumps was over $1,400, which does not include removal or refit.

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*********If by service, you mean rebuild I think you could have bought 2 new Jabscos for that amount. Quick searching online shows pricing as low as 500. each.**Parts and service seem a lot more expensive over there, than in the U.S.

I guess shipping is a big factor.* How much is diesel fuel in your neck of the woods?** JohnP

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