Too many hours?

[Gary Hill]

As others have said maintenance is the key. I will have no problem with my 390 getting over 1000 hours, its not a death certificate. A good friend of mine down the dock has a 36' Pursuit with 5500 hours (yes 5500 hours) and it is still going strong. Engines like to run and as someone posted above, I'd rather have higher hours that have been used regularly than one that has been sitting for long periods. Like a car, if you like to put your foot on the gas every now and then and crank a few revs, don't buy a used car from the little old lady from Pasadena who has never cranked it up. You will flat sport your cam in a hurry.

 

[sgs01]

1000 hours is not a death sentence at all. My 1984 SeaDancer with twin Merc 260 inboards has 1600+ hours and they still run perfectly.

Conduct a wide open throttle test on the sea trial. If the owner is reluctant to, then walk away as he is surely hiding something. If he does get them to wide open throttle, they should reach 4400-4800 rpm for that engine. If they reach wide open throttle and gauges look good, then chances are the engines are healthy. A compression check and oil analysis is also a good idea

Then, ask the operator to keep the engines at 4000 rpm or so for no more than a minute or so and watch the gauges. They should not be abnormal. Watch for symptoms of blow-by at that point.

Keep in mind that hour meters turn on and off with the ignition keys, while the cosmic time clock never stops. Lack of use hurts engines far more than use does. So a 30+ year old boat with low hours LIKELY means that it has not been used much, and will have a very short lifespan indeed due to internal corrosion from lack of use. Things start to rust, manifolds and risers start to corrode, cylinders corrode and rust from lack of lubrication, etc.

One thing to keep in mind about marine engines (especially diesel engines), is that they will not tolerate neglect. There is no such thing as a minor cooling system problem. Ask the PO for the maintenance records for the engines if he has them, especially any overhaul/rebuild records. Also remember that there is no such thing as an overhauled/rebuilt engine unless and until proven otherwise.

 

[BillK2632]

I look at hours for maintenance, not so much health of the engine. Like others have said, maintained correctly a gas engine should easily run 1500-2000hrs or more, before any significant repairs - IF MAINTAINED. My old Correct Craft had 1800+/_ hours on it when we sold it and it was running as strong as when it was new, my 290 400hrs no issues, our old Glastron with a 115 Johnson had to have had thousands of hours on it, no hour meter on it. My current 4.3 is about to tick over 500hrs, no issues whatsoever. I think the 1000hrs is a mental thing like 100,000miles on a car. I know car engines are run differently than marine, but I look at it this way - my Lexus has 125k miles on it and runs perfectly, if I do some basic math (125k / 50mph avg = 2500hrs) in reality I would say my car has more like 3000hrs on the engine - it is by no means at end of life. Again, different than a boat, but still somewhat relevant. The reality is most cars will run way past 100k miles, many over 200k and about any marine engine should last several thousand hours or more.

Boats even more so than cars will go to crap real quick if you ignore the maintenance. The reality is a marine engine is usually damaged by some other event (overheating, water ingestion, etc) long before it suffers from any significant wear. Same with a car, they rarely just wear out - usually some other event expedites the death. An example - that valve that dropped at 1500hrs probably has a root cause in an overheat that occurred at 500hrs and damaged the head gasket, from a failed water pump impeller that the owner thought they could get one more season out of - he shut it down as soon as he saw the high temp, but that was enough to start the ball rolling. And that seemingly insignificant event at 500hrs planted the seed for a blown up engine 1000hrs later.

The guy that says he has 500k miles on his Chevy pickup or the 1million mile Volvo didn't get there by changing the oil every 2k miles, or using Mobil 1 or Royal Purple - they got there by maintaining all of the engine systems - ignition, cooling, lubrication, etc on a reasonable schedule, with quality parts and treating symptoms, not making repairs after a breakdown.

 

[RickM]

Thanks for all the info and personal experiences.
I guess he I working on getting a boat with new manifolds and risers.

 

[El Capitan]

I must say this is a very important topic. There are tons of boats out there. Ask me how I know. I've been looking at boats for a year now. I'm originally from FL but now in Chicago.

I owned a 1989 242 SRV that w 454 Bravo many years ago in Fl. At 500 hrs I noticed blow by. I did all the engine maintenance, so I thought. The real killer to marine engines is salt water use. I noticed a leak in one of the risers so I had both replaced. The mechanic showed me what they looked like and it was shocking. The salt corrosion was significant after 3 years of use and the ride through canal to the marina where I dry racked it was supposedly brackish water. So I did not flush after every use. Big mistake.

Inspite of this blowback the engine ran at proper rpm at wot. The engine was shiny clean and no visible corrosion.

You never can tell the condition of an engine even if it runs properly unless you do the compression check.

Today im still waiting to find the right boat ie power and most definitely a fresh water use only for IO set up. I've come close couple times but didn't pull the trigger because I notice the rust in the seam between riser and manifold. I'm scarred from past experience on this particular service item because I know it's a common cause of eventual engine failure regardless of hours or appearance.

When i find the set up I want I will no doubt have a complete hull and engine survey especially compression check.