Why do people replace diesel engines in a sailboat?

[Compass790]

I'd love to replace our noisy, butt hammering,underpowered single cylinder Yanmar but don't have $10,000 to spare.
As for rebuilding, I'd say it depends on parts prices & how much work can owner do himself if not paid a lot at work. If paid a lot at work probably better to buy new but you have to weigh it up yourself.
If I had my rathers it would be a multi cylinder ( preferably 3) naturally aspirated, mechanical injection, kubota tractor engine based diesel to escape the likes of Yanmar & Volvos predatory parts pricing.
Electric propulsion has it's appeal but not the range we require

[nvmoose]

Originally Posted by Teknishn

I have been considering re-powering. Here's why: I have a Yanmar 1GM which is 6.5 HP. As a full time liveaboard and coastal cruiser I have kept up on the maintenance/repairs and the engine runs great. However, one of the complaints about the older Hunter 27's is that they were under-powered, which I've found to be true when fighting ICW currents, tidal flow, storms, etc. Have changed props as well to no real great effect. Great engine for getting to-and-from a dock, but not enough "umph" for cruising. I have room in my engine compartment to install a Yanmar 2GM20 (20 HP) with only minor modifications (lengthening the engine bed plates and moving my companionway steps forward 4.5-inches). No need to change the gearbox, electrical harness or engine controls. Additionally, parts for the 1GM have become harder to find. More pro's than con's in my case.

I have been considering a purchase of a 1983 27 Hunter Cherubini (my first boat)with a Westerbeke W 10 TWO that is not working. It has been diagnosed with low compression by two marine mechanics and it will not fire up and run. The PO has stated that it ran last season but then stopped. I have not seen the boat yet due to snow. This is a fresh water boat and has been in Lake Tahoe it's entire life. Price or the boat is $2700. From what I can tell by the pics it has been well taken care of and I thought this was a pretty good deal but the replacement or refurbish of the W 10 TWO has pretty much killed the deal. The PO received quotes of at 8-10k with a tranny overhaul. Is it possible that some back pressure or vapor lock could cause a low compression test to warrent a rebuild? Is there any tips or tricks to get the engine to fire up or is low compression a killer? Is repowering to a newer different engine a consideration in this small of a vessel? BTW I am not totally unfamiliar with sailing or marine lifestyle . My wife and I have sailed the San Juan islands, the Greek islands, and sailed from SF to PV and attended the Baha Ha Ha twice. We even threw in a Bash(ONCE)! from San Jose Cabo to SF. But we did this as Crew obviously and thought we would pick up a small boat close to home to enjoy. Hence the above predicament ... Any help is appreciated! nvmoose.

[rbk]

Originally Posted by nvmoose

I have been considering a purchase of a 1983 27 Hunter Cherubini (my first boat)with a Westerbeke W 10 TWO that is not working. It has been diagnosed with low compression by two marine mechanics and it will not fire up and run. The PO has stated that it ran last season but then stopped. I have not seen the boat yet due to snow. This is a fresh water boat and has been in Lake Tahoe it's entire life. Price or the boat is $2700. From what I can tell by the pics it has been well taken care of and I thought this was a pretty good deal but the replacement or refurbish of the W 10 TWO has pretty much killed the deal. The PO received quotes of at 8-10k with a tranny overhaul. Is it possible that some back pressure or vapor lock could cause a low compression test to warrent a rebuild? Is there any tips or tricks to get the engine to fire up or is low compression a killer? Is repowering to a newer different engine a consideration in this small of a vessel? BTW I am not totally unfamiliar with sailing or marine lifestyle . My wife and I have sailed the San Juan islands, the Greek islands, and sailed from SF to PV and attended the Baha Ha Ha twice. We even threw in a Bash(ONCE)! from San Jose Cabo to SF. But we did this as Crew obviously and thought we would pick up a small boat close to home to enjoy. Hence the above predicament ... Any help is appreciated! nvmoose.

For a lake boat I would install a gas outboard and call it good. Gas jobs deal with cold starts and short runs better ie starting and stopping within 15 min as you leave dock and raise sail. I would leave the original diesel in to maintain the trim and stability or remove and install equivalent ballast. I wish we had the aftermarket southerners enjoy. I would love to find a sub 30 footer with a trailer exclusively for lakes.

[slug]

Originally Posted by Chotu

Another thread got me to thinking. Why is it that people decide to re-power?

Assuming you have a working engine, a diesel engine, what is the point?

I see a lot of people pull out older engines and put in a brand new one. I’m thinking of ones like an old Perkins. Sure, they look old. And they probably don’t get as great fuel efficiency as the new ones. But why replace them if they are still running?

Expensive to repair

Hard to find parts

I just threw out a Cummins diesel generator

25 years old , 22500 hours

In very good condition

It’s defect was a worn flywheel ring gear , the starter motor couldn’t get a grip on the flywheel

to service , the generator would need to be broken down , lifted out of the boat , repaired then reinstalled

The estimate was about 50 percent
of the cost of a new generator

A new northern lights was installed

[stormalong]

Originally Posted by nvmoose

I have been considering a purchase of a 1983 27 Hunter Cherubini (my first boat)with a Westerbeke W 10 TWO that is not working. It has been diagnosed with low compression by two marine mechanics and it will not fire up and run. The PO has stated that it ran last season but then stopped. I have not seen the boat yet due to snow. This is a fresh water boat and has been in Lake Tahoe it's entire life. Price or the boat is $2700. From what I can tell by the pics it has been well taken care of and I thought this was a pretty good deal but the replacement or refurbish of the W 10 TWO has pretty much killed the deal. The PO received quotes of at 8-10k with a tranny overhaul. Is it possible that some back pressure or vapor lock could cause a low compression test to warrent a rebuild? Is there any tips or tricks to get the engine to fire up or is low compression a killer? Is repowering to a newer different engine a consideration in this small of a vessel? BTW I am not totally unfamiliar with sailing or marine lifestyle . My wife and I have sailed the San Juan islands, the Greek islands, and sailed from SF to PV and attended the Baha Ha Ha twice. We even threw in a Bash(ONCE)! from San Jose Cabo to SF. But we did this as Crew obviously and thought we would pick up a small boat close to home to enjoy. Hence the above predicament ... Any help is appreciated! nvmoose.

8-10 k sounds high to me. You could probably replace a two cyl engine for that price. Also, if you could get the engine out and to an engine rebuilder away from the marine trades the price would probably be more reasonable. One thing about Westerbeke is that they hide the origin of their engines and gouge on parts. If you can identify the original manufacturer of the engine it would save a lot on rebuild parts. There are a lot of boats for sale with the same situation. An engine rebuild or replacement is a deal killer.

[newhaul]

Originally Posted by nvmoose

I have been considering a purchase of a 1983 27 Hunter Cherubini (my first boat)with a Westerbeke W 10 TWO that is not working. It has been diagnosed with low compression by two marine mechanics and it will not fire up and run. The PO has stated that it ran last season but then stopped. I have not seen the boat yet due to snow. This is a fresh water boat and has been in Lake Tahoe it's entire life. Price or the boat is $2700. From what I can tell by the pics it has been well taken care of and I thought this was a pretty good deal but the replacement or refurbish of the W 10 TWO has pretty much killed the deal. The PO received quotes of at 8-10k with a tranny overhaul. Is it possible that some back pressure or vapor lock could cause a low compression test to warrent a rebuild? Is there any tips or tricks to get the engine to fire up or is low compression a killer? Is repowering to a newer different engine a consideration in this small of a vessel? BTW I am not totally unfamiliar with sailing or marine lifestyle . My wife and I have sailed the San Juan islands, the Greek islands, and sailed from SF to PV and attended the Baha Ha Ha twice. We even threw in a Bash(ONCE)! from San Jose Cabo to SF. But we did this as Crew obviously and thought we would pick up a small boat close to home to enjoy. Hence the above predicament ... Any help is appreciated! nvmoose.

all you have to do is figure out what Kubota block you have and have the local farm tractor dealer do the rebuild . Or you could repower with about any small marine diesel or rip it all out and go outboard gas . After all this is as you say just a local boat for sailing the lake close to home.

[Pete the Cat]

That diesel is ridiculously simple and here is a cheap option. You said the boat was generally well taken care of and run in fresh water, which suggests that it was not run hot or out of oil---which could have been the source of serious damage. I would take the head off this single cylinder engine and see i you have a stuck valve (which I would be willing to wager if the other statements are true). You could do this yourself or hire a knowledgeable diesel guy (inccreasingly hard to find these days) to do it. It should not take a lot of time to lap the valves, check the gap settings, and make sure the springs are OK. I have no idea why your two mechanics did not give you this option and that raises my suspicion about their competence if they did not.
Ray Durkee
T37 #373

[Rowglide]

I struggled on the question... rebuild or replace. But for MY particular case. Rebuild was the way to go.

1. Engine is a Perkins 4.236
This is an industrial engine used worldwide with excellent parts availability both OEM and aftermarket. Engine is also SIMPLE. No electronics whatsoever. If I can turn it over it can run.

2. with engine out, only needed to inspect, clean and paint stringers. No re-designing of engine mount area, access points or shaft length, exhaust system...

3. Cost. Using competent rebuilders and only Perkins parts, stayed way below 1/2 price of just purchasing new engine.

4. This is almost 1000lbs. If I put in a newer lighter engine, I might have to rebalance the boat somewhat.

5. Prop/trans/engine all perfected for boat over the last 40years. No puzzling over gear ratio and prop size and pitch. (I do have a MAX Prop but changing pitch isn’t a walk in the park)

[Exile]

Originally Posted by Pete the Cat

That diesel is ridiculously simple and here is a cheap option. You said the boat was generally well taken care of and run in fresh water, which suggests that it was not run hot or out of oil---which could have been the source of serious damage. I would take the head off this single cylinder engine and see i you have a stuck valve (which I would be willing to wager if the other statements are true). You could do this yourself or hire a knowledgeable diesel guy (inccreasingly hard to find these days) to do it. It should not take a lot of time to lap the valves, check the gap settings, and make sure the springs are OK. I have no idea why your two mechanics did not give you this option and that raises my suspicion about their competence if they did not.
Ray Durkee
T37 #373

This is exactly what I did on my 30+ year old Westerbeke generator that was also suffering from low compression and wouldn't start. I pulled the head off, had it refurbished by a good machine shop, reinstalled, and it not only started right up but runs a lot better. I pulled/reinstalled the head myself, and the machine shop costs totaled about $400. There's a chance this could all be for naught if it's the rings causing the low compression, but I was advised that refurbishing the head could actually bring the rings back to good health. I figured I was only risking some of my time and not a huge amount of boat bucks so was worth taking the chance. Something to consider perhaps.

[CassidyNZ]

Originally Posted by Pete the Cat

I would take the head off this single cylinder engine and see i you have a stuck valve (which I would be willing to wager if the other statements are true). You could do this yourself or hire a knowledgeable diesel guy (inccreasingly hard to find these days) to do it.

Yes, even just taking the rocker cover off would tell that story.

I was building a home-made genset using a Kubota 2-cyl which ordinarily ran really well. After leaving it standing for a protracted period, I came to start it and it ran really rough and clattered enough to be scary.

When I pulled the rocker cover off, discovered one of the rockers had popped off the valve stem. That caused the clatter and obviously that cylinder was not firing. Further discovered that the valve was stuck down, causing the rocker to come off/pushrod to jump out.

I got the valve unstuck, refitted the rocker, set the valve clearance and she was back to sweet running, no damage done. I guess this could be a problem if the valve meets the piston but I think on this Kubota that doesn’t happen.

Worth a check though . . . . on a single-pot engine, clearly this would prevent the engine running.

[CassidyNZ]

A friend had a Ford Lehman engine, 100hp I think, that used a couple of litres of oil during a 3-day motoring session. It also smoked a bit on cold starts. Other than that, it always started first touch, never missed a beat, super reliable, super smooth. Being a man with more financial means than mechanical nous, he decided to re-power.

Used a new Yanmar 4JH4-HTE also 100hp (or thereabouts). I was involved with taking the Ford out and restoring the boat after the Yanmar agents had installed the new engine.

Whilst I’m not sure of the final cost, I believe to have been north of NZ$35k. And the old engine had zero commercial value, was donated to another boatie who had similar in his boat and thought it would be cool to have a spare.

I recall the boat costing around NZ$82k when he bought it. My comment was that I can buy a fair amount of oil for $35k. And I would probably never motor for that long

[gonesail]

Originally Posted by newhaul

all you have to do is figure out what Kubota block you have and have the local farm tractor dealer do the rebuild.

some of the westerbekes were marinized mitsubishi .. like mine .. K3D.

[Exile]

Originally Posted by gonesail

some of the westerbekes were marinized mitsubishi .. like mine .. K3D.

Ditto on my genset -- Mitsubishi Model K3D. My propulsion engine is a marinized Mazda 3.0L (based on a Perkins).

[Thumbs Up]

Find out the exact circumstances of when it stopped running. Find out if these "marine" mechanics actually pulled the injectors and performed a compression test with a strong battery. An engine like that that "just stops running" is likely from a fuel problem, could be a bad lift pump or air in the or a dirty filter. Verify that the glow plugs are working. An engine that has been sitting could fail a compression test simply because the cylinder walls are dry.

[nvmoose]

Originally Posted by Pete the Cat

That diesel is ridiculously simple and here is a cheap option. You said the boat was generally well taken care of and run in fresh water, which suggests that it was not run hot or out of oil---which could have been the source of serious damage. I would take the head off this single cylinder engine and see i you have a stuck valve (which I would be willing to wager if the other statements are true). You could do this yourself or hire a knowledgeable diesel guy (inccreasingly hard to find these days) to do it. It should not take a lot of time to lap the valves, check the gap settings, and make sure the springs are OK. I have no idea why your two mechanics did not give you this option and that raises my suspicion about their competence if they did not.
Ray Durkee
T37 #373

Thanks Pete, that's exactly the kind of information I was looking for…
rbk... As far as an outboard goes, Tahoe is very particular about not allowing 2 stroke outboards so I would need a four stroke. I like the idea of pulling the valve cover to inspect the rockers, valve stems, and springs. After all the Owner did say that the engine ran last season. So now all of a sudden it doesn't? Any suggestions on how to determine how to identify the base motor?
Thanks again, nvmoose