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


Jul 14, 2010
Has anyone done through a re-powering project recently? I am looking at replacing a Perkins 6-354.4 135 HP naturally aspirated engine in a 43 ft full displacement trawler (approx 42.000 lbs cruise loaded) and am seeking input from anyone who has gone through similar process. Lessons learned? Do's & don'ts? New vs re-built? Other manufacturer's engines.....Deere, Yanmar etc. Any help greatly appreciated.
Whutcha going to do with the old one?
Don't know yet. May exchange or if go with different manufacturer will put on the market.
Look for an engine of about 95hp. All engines are good but there is a bit of a range on the quality of conversions and they are all conversions. Join and read about the engines and the comments on the forums by experts and others. I joined BD a few months ago and have'nt been there much but I'm already re-powered. Klassen Engines may have something for you**** ....the're made in Canada. Ther'es a Fisher on yachtworld with your displacement that has a new 85hp Deere. The Nordhavn 46 came w a 101hp Lugger. Look at all the boats like yours (mostly regarding displacement) that you can find regarding disp and compare. If you have lots of head on windage such as a motor sailer another 10 or 15 hp may be better. If your hull is more efficient than a Krogen 42 or a Nordhavn 46 75hp may be all that you need. In my opinion engine speed should not be an issue but use the calculators on BD to see what reduction ratio you will require to swing the propeller that is best for your boat. If you chose an engine much lighter than the original consider CG and ballest. Again** ..go to Boatdiesel. You'll be lucky if Larry M responds here.
Not rrecently as it was 11 years ago, but I did replace a Perkins T6.354 with a Cummins 6B series. The footprint of the Cummins is almost identical to the Perkins I can tell you that.

At the time MY rule of thumb was that if the rebuild approaches half the cost of new then go new. I was there with the Perkins so it was a no brainer for me. However figure some extra $$ for changes in raw water thru hull, exhaust, etc when you change engine brands and HP levels (if you go UP in power).

BTW I sold my old enigne for some really good dollars and also made lots on all the spares I had accumulated over the years which included a complete spare (good) enigne block. TAD (out of Va) buys good used blocks to do rebuilds if you don't find another buyer for your old iron.
I will add that the Cummins staright 6 without the turbocharging is 115hp and I would imagine it would be an excellent choice. They are just rare....and don't know if you could find a rebuild through Cummins.

Don't forget about American Diesel either. Their replacement for the Lehman is 140hp and if the Perkins is similar to the Lehman, then it would be similar to this engine.

Not all Yanmars are turbocharged.

Don't forget about Westerbeke as they make some good small engines.
"Don't forget about American Diesel either. Their replacement for the Lehman is 140hp "

I have read that this is no longer available as of last year.
Do you need the engine delivered and ready to install?

Or can you scrounge and jiggle and do the install yourself?

There will be a 50% to 75% savings IF you find , assemble and install vs purchase from the boat store.

If rebuilt is OK with you (as it is with almost 100% of commercial boats) the savings will be about 50%.
What about the Vetus Diesel engines?* Doe's anyone have info about them?

Whiskers wrote:
Has anyone done through a re-powering project recently? I am looking at replacing a Perkins 6-354.4 135 HP naturally aspirated engine in a 43 ft full displacement trawler (approx 42.000 lbs cruise loaded) and am seeking input from anyone who has gone through similar process. Lessons learned? Do's & don'ts? New vs re-built? Other manufacturer's engines.....Deere, Yanmar etc. Any help greatly appreciated.
*Here's most of*a post I did last Novemeber.*
I recieved* an*estimate from*a Ford Lehman dealer to do a total rebuild for $9,800.00.* This doesn't include removal or re-installation.

At the same time I*heard back from Lugger/Northern Lights to replace our SP135.* Here are the numbers to compare for a rebuild or replacement:

G'day, Lena and Larry.
We would have several recommendations for you to consider, and really what it comes down to is your cruising speed expectations along with the required hours of durability, or cruising range either at normal operating RPM, or for extended range operations.

First, visit our web-site, www.northern-lights, and under Lugger engine models L1064A or L1066T engines copy the brochures, for reference. In addition, for purposes of consumption comparatives, remember that 1 gallon of diesel should produce 20HP at the transmission input shaft, with a 3% estimated parasitic loss in the transmission.

Taking your average fuel consumption of your Lehman Ford, probably somewhere between 2 to 3 gallons per hour, you were using 40-60 HP to cruise your KK-42 between 7-8 knots, and when you compare this to either engine performance, your would be operating your engine at less than 50% of the rated capacity for the engines.

The physical dimensions of the engines will compare very close to your existing Lehman, the L1064A engine would be shorter of course, since it is only a 4 cylinder engine. To elaborate further, both Lugger models begin life as John Deere Industrial engines, then we marinize the engines to suit our requirements which are somewhat different from the standard John Deere Marine engines, also available to you and standard on all current KK models. Since we have been marinizing the Deere engine for 25 years longer than Deere, we think we know something about what is required for our customers, so we continue to use their engine, done our way.

So you will have options, from very limited changes in the scope of supply between your existing engine, 12V, single high amperage alternator, HE cooling, Twin Disc or ZF transmission with a 2 1/2 to 1 reduction gear, wiring harness, panel, wet exhaust elbow, all matching what you have, so it can slip into the engine spaces without any severe compromises. But, what other changes would you wish to make, such as stabilizers, thrusters, dual alternators, drive options for other solutions, and etc, that you would want to incorporate into your repower project?

Pricing will range from $34,500 to $39,000, depending upon the model selected and the transmission requirements, and available accessory options tailored to your requirements.
Fit should be very close to your existing Lehman, and if you wish to receive a quotation, we would first request that your complete the application questionnaire available on the web-site.

I hope that you will continue your interest and respond with a quotation request that results from receiving your questionnaire. You may be directed to one of our offices that may be closer to you, so if an inspection and consultation is necessary, we can accommodate your interest and timing.

Thank you for your interest and we look forward to your response.

Regards, Steve Scholz,
Director, Asia Pacific Marine Market





I've looked at the Vetus line. Their 42hp engine is the same Mitsubishi engine as my Klassen. Their 54hp is Isuzu. They look like very good engines


The big heavy slow turning engines are great*** ...and very expensive. And they will be good for you if you can afford them and good for resale when you sell your boat. BUT much more economical engines can be had and the probability that you will need an engine that will go 24000hrs is very unlikely and these higher speed engines, as David M says "high reving, highly stressed" engines will go well over 10000hrs if taken care of. You may be able to get a new engine from Klassen for almost as much as the rebuilt Lehman. Good as the Lehman is it's still a 1950s engine. Klassen sells a good lineup of engines for prime power and even more for generators and other stationary cannery use ect. The fishing fleet in Alaska have been running Isuzu's for many decades marinized by Klassen.*
Take into consideration who will service an engine if you buy a new one. Is there a dealer not to far from you? Does that dealer have a good reputation and will they be able to take care of your needs? If you have the best engine in the world but no dealer nearby to get parts and service from, a different engine might be better for you. Will you be travelling where it might be hard to get parts?
There are some very good engines that are not well known but when it comes time to sell the boat an off brand will hurt the value. FF often talks about the in and out costs and a more expensive engine with a good service network may be less in the long run.
The place was H & S Marine Services but they shut down about a year or two ago. Too bad as there were several folks interested and I was one.
Now several other sites but not the correct one , come up. I think his site is simply gone as the question has come up on Boatdiesel for the same results.

Unless there is someone new.

That's one of the great things about Klassen. Most of their customers operate their engines 1 to 3000 miles from the shops so they know how to service in the field. The fishing industry is allergic to down time and Klassen's been taking care of them for over 30 years. I don't think it's the size of the company representing your equipment but how well do they do and how long have they been doing it. One of the reasons I deal w Klassen is the good service they give in Alaska. Those that know Boat Electric in Seattle know of what I speak.
Klassen sells lots and lots of smaller Isuzus and Mitsus. The've sold Isuzus in Wash and Alaska for 3 to 4 decades. They have 130hp (about) engines too but I can't remember thier brand. Call David Rowland at 206 784 0148 or 1 888 784 0148. Klassen Engine Co is located in Surrey (near Vancouver BC) I think but David operates the store/shop in Ballard (Seattle). Much to consider making a conversion. High/low starter, bellhousing and crankshaft coupling and available water cooled exhaust manifold are key factors to an easy conversion. It will, however, probably be easier shopping for a used marine engine instead. There's lots of older 120hp or so Klassen/Isuzus out there waiting to be found. Most will be in BC.
A friend forwarded this to me recently from a rebuild that was done last summer (2010).* Interesting numbers.*
"Just completed (3 weeks ago) my replacement of my Perkins 4-236 with the Yanmar 4JH4-TE 75 hp. Costs to date: $13,800 (bobtail), $3800 to install with custom engine mounts to raise engine to suit centerline of shaft, $900 to fabricate exhaust riser(dry) to meet Yanmar exhaust system criteria to maintain warranty. $600 to service and install the BW tranny with 2:57 gear ratio, all this effort to be able to spin a large prop (20x18) to cruise at 6-7 kts at 2000 engine rpm. Goal of project is to reduce noise and vibration, fuel usage.

Somewhat disappointed in noise factor (note:my engine room has zero sound insulation), I expected more improvement. I'm sure I'm guilty of too high expectations. I will have to put in insulation in the larger engine room space and or an engine box.

Fuel consumption seems improved, haven't done enough testing to effectively measure though.

Boat rides 2-3" higher due to difference in weight (600#).

Considered the BETA 75 (equivalent to my Perkins 80 hp), but the Yanmar was cheaper by $2000. Rebuilding the Perkins was also considered, but for
$8-9,000 and I still have a 45 yr old engine block whose service record was not recorded, I felt my resale value of the boat with the new Yanmar was enhanced."

-- Edited by Larry M on Saturday 9th of April 2011 07:45:37 AM
The Beta (a Kabota) is an excellent engine**** ....but so is the JH Yanmar.

David*** say "The Beta would be worth every penny of its $2,000 extra cost"

How so?
Well*** ..I do agree about the turbo and after cool. You have a point there. I was thinking about the 55hp I guess. The " big iron, slow turning" part is something we don't need to pay for and I'll guess it's kinda like a Harley motorcycle. People just like the big guns and authoritive sound they make. No need to ride a motorcycle w a 50 yr old engine. No need for our trawlers to be "long range" either. I think you have trawlers and passagemakers mixed up. Most all trawlers have fuel so readily available long range is not part of the equation. Again, you're right about the turbo engine. It's like manual roll up windows and a standard transmission. No other choice. Sure glad I got an NA engine. David, do you know why small NA engines are available and larger ones are'nt?

Seems I've been told the reason for the turbo's is that the engines won't pass EPA tests without the turbo. That makes me wonder how my NA Mitsu passes w/o the turbo.
Boat rides 2-3" higher due to difference in weight (600#).

Most boats with a 30 ft LWL will need a 800-1000lbs to immerse one inch.

This must be one tiny boat to get 3 inches out of 600 lbs!!
Top Bottom