How many hours is too many?

[Cowpoos]

Originally Posted by kenbo

Interesting post. Cowpoos, methinks you are confusing the Universal M-25, a marinized Kubota D850, with a Perkins M25. I've never rebuilt a Perkins M20, M25 or M30. No argument that they are marinized Shibaura engines but they are not the base engine for the Universal M-25 which is the focus of the OP. Sorry for your confusion but you must read the posts of others more carefully before you throw stones.

I am truly sorry Kenbo, I had no idea [clearly] that Universal made a marine engine also called the m25 and that the M25 the OP opened discussion with was something else other than the Shibaura based engine.

Sorry, I presumed to quickly you were one of the armchair experts types on this forum.

[kenbo]

Originally Posted by Cowpoos

I am truly sorry Kenbo, I had no idea [clearly] that Universal made a marine engine also called the m25 and that the M25 the OP opened discussion with was something else other than the Shibaura based engine.

Sorry, I presumed to quickly you were one of the armchair experts types on this forum.

No worries, I had assumed the confusion. You are truly a gentleman for the apology. Lesser folk would have faded into the ether of the internet.

[Group9]

The problem is knowing how they were maintained and used. We sold our last boat with a Yanmar 4JH BE with 7500 hours that was still perfect as far as I knew. But, I’ve seen them shot with 2500 hours with poor maintenance or worse it seems, lack of use.

[skenn_ie]

A million miles is quite common for (commercial) trucks. That, if you assume is an average of 50MPH (also not uncommon outside the USA), is 20,000 hours. Clean diesel and regular oil changes are essential though. OK, boat engines will be run at higher power settings than trucks though, so 15k should be reasonable.

[Pete the Cat]

Originally Posted by pbyrne

I'm looking at a 91 Catalina 30 with an M25 that has about 4000 hours, alternator and injectors done in the last 2 years. Fresh water.

What should I be looking for with respect to condition, other than the obvious things like leaks? Apparently it was 'looked after' but I'm uncertain how many hours before a rebuild, and what other parts may need attention with that many run time hours. Shaft bearings etc.

Also, what's the typical cost to rebuild, assuming you do it in boat.

Hours is a lousy measure of the health of any diesel engine. Diesels in use in industrial applications run for 10s of thousands of trouble free hours. The problem with recreational marine diesels is the owners and the owners' use of them. If the engine was used only occasionally to get in and out of the slip it will not take a lot of hours to collect moisture that will corrode and degrade its performance. If the engine was overpropped (as many production boats are) it will have been lugged through it hours and probably has some awful carbon build up that will shorten its life. And, of course, there are those things like regular oil changes which some owners seem not to care much about. But one of the biggest bugaboos is the cooling system (heat exchangers) of these small marinized tractor engines. Especially if run in salt water they all clog at some point and the cooling system becomes compromised--the actual engine blocks really do not fail that often--it is mostly the cooing system or fuel systems that are the problem. Soooooo---I would be looking to see if the engine looks like it has been taken care of---it is hard for an owner or broker to cover up the neglect an engine gets in its life. I would try to learn how the previous owner used the boat--did he go on a long cruise (where the engine hours would be at constant temps and therefore less of an issue)? Was it run in salt or fresh water? Does the engine start right up, or does it need a lot of revolutions to catch? A little blue smoke is normal, but a cloud is a problem. Are there visible leaks of oil or fuel after the engine has been run. Personally, I would not pay much attention to hours as I would to these issues. Used boats are cheap and a recent repower should make a boat much more valuable (if done correctly--which many are not). But if an engine starts quickly, does not leak, blow large quantities of blue or white smoke at start up--I would probably go with it. My belief is that "engine surveyors" really do not do much more than look at these things. It is very difficult to do compression testing on a small diesel and I think it would not likely give you much information anyway.
After you buy a used boat with a diesel,I think it is a good investment to service the cooling system of whatever you buy. Go through it yourself with the guidance of a competent mechanic. Marine diesels work in a hostile environment and under obnoxious conditions and require much more attention than your car engine.
FWIW.

[Paul Annapolis]

If I may so, with all due consideration.....You are buying a SAILBOAT! An auxiliary sailboat--a boat with a big keel, big rudder, mast, spars, rigging and SAILS. And the boat is 30 years old--not just the engine!!! The engine is "AUXILIARY". If it were a powerboat, you would still have many other concerns , but the propulsion would be key. Not so with a sailboat. I suggest that you not worry too much about the engine. If it starts easily, doesn't shake or vibrate, throw a lot of smoke etc etc..then if you pay the right price with its age in mind, when it goes south...you would have expected it as such. Instead of asking us for a hundred opinions, hire a mechanic for an engine survey and oil analysis. BUT...the rigging, sails, deck hardware and bedding, rudder and steering--these are probably more important, more critical and could be as expensive or more expensive than a major repair of the engine (in which case, replacement may be the better option instead of overhaul--could be $20k????). When was it last re-rigged? What about condition and inventory of sails, deck core etc etc.? Have you sent a rigger to the masthead? I would guess that the seller does not know if the boat was ever re-rigged. Sounded the rudder? Wiring? Hatches and portlights? After 4000 engine hours, I'll bet the rudder has some issues. So, to sum up--it's a sailboat!! Focusing on determining condition of those things that make it a sailboat may be more important than engine hours. AND..how many hours do you expect to put on the engine each year versus on the rig and sailing? Going down the Ditch is one thing but putting in and out of the marina is another. It could throw a rod or blow a cylinder one day, but isn't it more likely to just slowly wear away? On the other hand something as simple as a missing or corroded cotter pin or cracked chainplate could do more than just ruin your entire day! Please keep us informed.

[CaptBobR]

As a surveyor, I do oil analysis on anything over 3000 hours and compression tests on anything over 12000 hours. Expecting 10000 hours off a diesel is realistic. If you can, find out the boat’s Sailing habits. Engines run at 70% with religious routine maintenance can last a long time.

[DeValency]

Originally Posted by pbyrne

I'm looking at a 91 Catalina 30 with an M25 that has about 4000 hours, alternator and injectors done in the last 2 years. Fresh water.

What should I be looking for with respect to condition, other than the obvious things like leaks? Apparently it was 'looked after' but I'm uncertain how many hours before a rebuild, and what other parts may need attention with that many run time hours. Shaft bearings etc.

Also, what's the typical cost to rebuild, assuming you do it in boat.

*******
If well maintained by the book and well used, a good diesel engine should do at least 10,000 hours.
Rebuild? Depends on who does it and what exactly is done. Can be $4K and up to a price of a new engine. But in your case, doesn’t look like you need to worry about it.
Go sailing!

[merrydolphin]

Many opinions here so I won’t give mine.
Here is my actual experience so far: Ferryman 25 HP 1960 vintage 15k hrs. Output shaft went. Still running good. Replaced due to lack of parts.

Perkins 4-154 purchased with 4300 hrs, sold with 11k hrs running quit well. Buyer had engine survey by Perkins shop, oil analysis etc. survey said normal wear and good for another 10k hrs if properly maintained.

Perkins 2-236 ( great engine) 12k hrs when purchased, vintage 1973. I put another 6K on engine. So I sold it with about 18k hrs. New owner traveled from La Paz Mx to HI, to Vancouver, to S Pacific, and eventually back to Vancouver. All on original engine. He said he did a valve job and nothing else internal. Still in use. I have no idea how many hrs now. The boat had about a 1600 mi cruising range under power, so he didn’t have to hold back much on use while making crossing. We never did. The boat was a Cal 2-46. (My favorite live aboard cruiser).

Ford Leaman 90 hp. Bought with 6K sold with 12hrs still running great. Great engine, no problems. On 1980 Eagle 32 Trawler.

Westerbeke 40. 34 HP. No idea of hrs. Seller lied to me on hrs. Was a Tartan 37 1981 vintage. I’m going to guess 6-8k hrs. Still running good currently.

When I bought my KP 44 with the Perkins 4-154 62 hp I was worried about the hrs at 4200 ha ha. It was just well broken in. I think one reason that I have had good longevity is that when I put hrs on, it wasn’t just to get out of the marina and back. I covered miles. With the KP 44 I ran crewed charters in the SE Caribbean. That meant hard motoring against the trades to meet my next guests. Diesels love to work! I didn’t go crazy with the power but I certainly didn’t baby them.

[CriO61]

Hi there! We have a 1989 Catalina 34' with a Universal 25XP. It has about 3700 hours. We are not the original owners. We had to replace the mixing elbow last year, there is a small oil leak that we can't get to and the biggest problem has been white smoke coming out the back. Thought the problem was injectors so we replaced them and there is still smoke.
So, all that to say, I would be prepared to have a budget because things will start to break and need to be replaced. While doing the injectors, now my husband can't get rid of a small diesel leak so, you might want to have a real mechanic around too, haha!!
Good luck!
C

[sailingharry]

Originally Posted by mvweebles

Bilge should be dry.

Oh for the Nirvana of a dry bilge. Oh, what an aspiration!


But I've never seen a keel stepped mast that couldn't dump a gallon in the bilge in good rainstorm. Mine will go from dry to running the bilge pump (which means 2") in a single day.


I suspect you'd have better results with a wooden mast, or at least one without internal halyards. But all the holes in a modern aluminum mast are a challenge!


Harry

[Shaneesprit]

Originally Posted by SVHarmonie

There is no way to answer the "how old is old" question. The last two boats I have owned each went over 10,000 hours, and are still going without ever opening up the engine. Other engines are dead before 4000 hours.

For a mistreated diesel engine, 4000 hours might be old. For a well cared for one, it is not even middle-aged.

Look for: Good compression. Good oil pressure. An oil analysis might find a few problems.

To keep it running:
Clean fuel.
Oil changes.
Adjust valve clearances on schedule.
Change timing belt on schedule.
Avoid overheating.
Avoid running cold.
Maintain the exhaust system to keep water out of the engine.
Let it warm up before running hard, and after running hard, let it cool down before shutting down.
When running long runs at cruising speed, open up the throttle to full every couple hours for 15 minutes.

In general, replace things like water pump impellers and belts BEFORE they break and cause other problems.

LOOK at your engine every day you use it. Preferably while it is running.

That’s the correct advice 👍👍

I would add it’s probably half way through it’s life, 8000 hours is generally what’s an Engine is expected to last. Of course they can last longer or less time, but that harder running is essential.
No one ever left their car ticking over but so often with Gens and boats that’s what people do ( I have to admit I did once leave my car on idle on the street because the battery was a bit low, next day when I realised - the only thing missing was my petrol ⛽️ lol )

[MicHughV]

This thread needs to take into account that a diesel engine is designed to operate at a certain rpm or duty cycle...even though a diesel engine may be rated to go to 3,500 rpm...it will have lower rpm duty cycles...depending on make and model of engine....

Even the best diesel engine made will self destruct if ran at rpm's beyond what the manufacturer recommends for long and interim duty cycles.

Diesel engines and the fuel injectors that run them are built with extremely fine tolerances and are generally very robust.

Much has been written about running a diesel at low rpm....for charging batteries, etc or not shutting a diesel down correctly. These instances are all detrimental to a diesel's lifespan.

Diligently changing oil, checking water separators, etc are key.
Diesel engines are built so robust to handle the usually very high compression and diesel detonation, that actual part failure is hard to imagine.

A diesel fuel injector is a device made with tolerances so small, they cannot be seen with the human eye. Feeding this device with water tainted fuel is an invitation to trouble.

Why wait for an raw water impellor to wear out ? Replace at routine intervals and avoid the drama.

Having said all of the above, a diesel engine that is properly run and properly maintained can run " forever"...but alas, I've viewed many boat diesels that are kept in some dank, dark cave with little or no maintenance, with owners cussing out the engines's shortcomings instead of looking at their own maintenance shortcomings.

[Cadence]

This whole thing is hypothetical.

[David Mathis]

Only 4000 hours on a diesel is low. It matters little if it’s generator hours or propulsion hours. The only catch is maintenance. Check the maintenance log. How often was the oil changed? Every 100-150 hours, you’re ok, every500 hours, not so good. Was the filter changed with the oil? Take an oil sample and have it analyzed. It will tell much about the condition of the engine and specifically the bearings. It’s a cost effective measure for boat buyers.