Sea Trial - Diesel Checklist

Hi there,

I'm new to boating, having arrived here via the sea kayaking world and am no mechanic. We're sniffing around a 30' boat and are getting close to taking it out for a sea trial.

A brother-in-law is a retired mechanic. He's worked on diesels both big and small his whole career, and is coming along with us to check the engine over.

Boat is 1982, engine is a 1995 Yanmar 4JH2-UTE 100hp turbo diesel. The boat hasn't left the marina in 2 years...the owner isn't able to take it out, but the son who is a mechanic has been looking after it.

I found the following PFD at Seaside Marine Surveyors - Welcome to Seaside Marine Surveyors

http://www.seasidemarinesurveyors.com/uploads/Surveying a Diesel Engine.pdf

Seems thorough...what do you think? Would you add anything?

Murray

The GENERIC list is good, especially the full load testing part which should be good reading for the cruising prop advocates. But you need a Yanmar list and expert especially one familair with Yanmar specific turbocharger and HX systems. How many hours on the engine and can you get the full service history records?

If the boats in salt water and hasn't left the marina for two years the prop my be full of barnacles. The hull may not be very clean either effecting your sea trial adversly.

Dave

If you're seriously considering spending a sunstantial sum of money on a used boat, hiring a qualified marine surveyor to inspect it is highly recommended. Figure $20 per foot more or less, $600 in your case.

Your brother in law may be able to provide some advice on the engine, but that's just one thing to consider when purchasing a boat.

In addition to a qualified marine surveyor, I'd get an engine survey performed by a qualified diesel mechanic. You'd end up with 2 reports. The engine survey would take place during the sea trial. If the boat has a generator, he would also survey that.

Thanks for all the good points.

Unfortunately, the closest marine surveyor lives about 300 miles away and only comes here when he can "bundle" a few together. We'll have to see if he's going to come out before winter sets in.

The marina is right next to a large estuary, so the fresh water keeps the barnacles at bay. The bottom has a fine, 3/4 inch long green furry pelt going though.

We did hire a surveyor for a boat in Vancouver this summer. The owner, the surveyor and myself were sitting on the boat chatting and after the survey, when the surveyor said, "Is there anything else I can do?" to which the owner said, "Yah, you can get off my boat!" That survey sure brought the price down.

While the logistics of getting an engine surveyor to your area are certainly frustrating the fact remains that a qualified engine surveyor who's familiar with the type of engine(s) in the boat you are interested in is your best defense against getting a problematic powertrain, particularly if one is not that familiar with these powertrains.

As I've expressed before, I'm not a fan of the internet as a source of reliable information on which decisions with significant economic risk will be based. The internet is just words on a screen. Unless you happen to know the author personally or are 100 percent sure of his/her knowldege or experience there is no way to judge if what someone is saying is accurate, made up, opinion, supposition, rumor, or armchair theory.

So while internet content on marine diesels may spur thought or research in a certain direction, I believe in seeking out one or more opinions directly from people in the industry before making any decision or taking any action, particularly with regards to large expenditures like a boat purchase.

We paid the airfare and expenses for the head of the engineering department at Northern Lights/Lugger to take him with us to California when we inspected, sea trialed, and had surveyed the Grand Banks we have today. While we hired a hull and an engine surveyor it was worth it to us to bring along a pair of objective and very experienced eyes to check out the boat and evaluate what the surveyors did and reported. Taking our friend with us is still one of the best investments we have ever made.

While this may not be practical or possible for others, I feel that at the very least anyone contemplating the purchase of a diesel cruiser should invest in hull and engine surveys regardless of the logistics of doing so. Without them it's a crap shoot, particularly for people like me and my wife who at the time were complete novices to this kind of boat.

In a perverse way,the most money saving reports can be those that cause you to reject a boat on the grounds of costly defects, or enable you to renegotiate on the basis of estimated repairs for defects not disclosed by the owner, who usually represents the boat to be in great condition.
The mechanical check can cost less than the general survey, if your doubts are mechanical do it first, but definitely do both before you finally commit. BruceK

there is the other school of thought also....

surveyors don't give guarantees and often miss the big ticket items anyway....so you pay twice...once for them and for the repairs too (unless you want the hassel to go after their insurance). to be fair...without destructive testing...finding big ticket items can be difficult.

a decent checklist from the internet or published paper and a good eye with someone who knows boats can often be as good or better than some surveys.

so you roll the dice either way...many of my friends would probably never use a surveyor but have to for insurance purposes. I'm pretty sure a member or two here became surveyors just for that purpose (they were in remote areas too...I think Skiperdude is one of them)

On most diesel boats some very simple observation may indicate a problem, the exhaust color.

White smoke on start is normal, esp if its cold , 40F or below.

IF the smoke clears up quickly at under 120F circ water temp , probably no compression hassles.

If it takes 160F to clear , the engine compression is not great , rings at least , inframe if its a real HD engine .

HOWEVER

The white smoke will only be some higher oil consumption and perhaps a bit poorer fuel use , and perhaps harder starting in real cold.

Worn out cylinders can be lived with for a decade , depending on hours per year.

White smoke suddenly underway , probably water in cylinder, head gasket?

Black smoke underway is sign of an overload or bad injector. Pull back RPM!!!

A fish killer on acceleration will almost always blow mucho black smoke as it gets past the hump, no problem.

.

If it takes 160F to clear , the engine compression is not great , rings at least , inframe if its a real HD engine .

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I can't agree with this

The 4jh have a reputation as a good long hour engine. Usually in big sailboats and workboats.

It's a 3600 rpm engine in a trawler. It may have run at low rpms for a significant amount of time or run at idle at the dock for the last couple of years.

Not great for the rings if it runs underloaded, and there might be excess oil consumption. If you can, have the owners rep seatrial with a heavy load on and get the temperatures up. Make sure it reaches full rpms.

I'd pull the exhaust elbow and look into the turbine to see if it is coked up. Check for axial and angular play. I'd also look into the impeller side to see if there is any oil in the scroll to indicate the condition of the seal.

Keep in mind the fuel is also going to be two years old as well. Old diesel tends to smoke more (whitish grey, NOT black), and keep an eye on the filters for water and asphaltenes that have settled out.

All the above has good advice even though some seem contradictory.
A survey is a must if you're going to invest the money necessary to purchase a 30+ foot boat. But a survey is only as good as the surveyor and even a good one can't tell you everything wrong with the boat.

Engine surveys can be misleading. My survey come back with oil samples that were not perfect. Further investigation determined that this was not significant. The internet boat forums are full of stories of certified Cummins, Cat, Yanmar (insert your own engine brand) mechanics whose approach to fixing things are to replace items until it works right. In many cases these are the same mechanics that survey engines.

Relying on the advice of one person can be risky and may result in the loss of a good boat or avoiding a bad one. Like everything else; buyer beware.

Unlike Marin, I rely on boatdiesel.com forum for mechanical advice over a mechanic. I've had good results using this approach. For issues other than engines TF is a great resource and has been helpful with some engine issues too.

Good luck.

Northern Spy said:

I'd pull the exhaust elbow and look into the turbine to see if it is coked up. Check for axial and angular play. I'd also look into the impeller side to see if there is any oil in the scroll to indicate the condition of the seal.

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Unless one is familiar with the make and model of turbocharger being inspected, guessing by fingertips about the axial and radial play might be very misleading. Axial play on a perfectly good turbocharger can be several thousandths of an inch and radial can be much more.

If oil is present on the compressor impeller and inducer it probably comes from the engine breather, not the turbo seal. Any leakage from the seal will find its way behind the impeller and into the volute, it would have a difficult time reaching the face of the impeller.

The inlet area just ahead of the impeller is often "wet" with oil since the pressure drop in that location will cool the air and condense oil vapor.

If the exhaust side is wet with oil it could be from the turbo seals or it could be from bad valve seals. It is it wet it is from idle running since at load any oil would be burned off pretty quickly. A lot of carbon deposits is not a good sign as it indicates oil in the exhaust and will eventually unbalance the turbine.

As a general rule, turbochargers on recreational diesel engines are pretty much bullet-proof.

A good survey kept us from buying a boat with a saturated flybridge and an engine that would not come up to rpm. Engine failed again after a visit from the service man. Best $900.00 I ever spent.

Rob

Thanks for all the posts...much appreciated from way down here at the bottom of the learning curve.

Still haven't gone on the sea trial yet, as the owner is out of country.

People should bear in mind that this is happening on BC's north coast, about a 6 hour round trip drive from the nearest surveyor, and there is only one very busy marine mechanic shop in town. Slim pickings.

We have the last survey, done in 2009 when the bottom was painted, and it reads more like a boat magazine article than a real survey. (I really don't care what the seat cushion material is made of). We did get a survey done on a boat we almost bought in Vancouver, and even though the deal fell through, the money was definitely not wasted. The surveyor up here hasn't returned my calls.

Everything about this boat oozes with the care and attention of its one and only owner. The outside surfaces show their age, but everything from the bilge up on the inside is near pristine and clean...well...except for the fuel tanks which look original. (I'll be seeing the maintenance log at our next meeting).

I'll keep you posted.

Out of curiosity, when you say north coast BC where do you mean?

Marin said:

Out of curiosity, when you say north coast BC where do you mean?

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I'm in Kitimat, perched on the edge of Paradise.

MurrayM said:

I'm in Kitimat, perched on the edge of Paradise.

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We've never been back in there with the plane. Is there road access to Kitimat from Bella Coola or is it boat or plane only?

We're about 32 highway miles south of Terrace, and from there it's a left hand turn to Prince Rupert, or a right hand turn to Prince George which is 500 miles away. (The only way to get to Bella Coola by road from here is through Prince George).

Okay. I was looking at my iPad's map app totally incorrectly. It has a dot for Kitimat out in the boonies some distance from the actual streets that make up the town at the head of the inlet. So I got this notion that the streets were Bella Coola and the dot labeled Kitimat was a remote settlement farther down the inlet. Turns out the streets are Kitimat and once I zoomed out I realized that Bella Coola is much farther south at the end of BC20.