Looking at a boat but questioning it's engine hours?

Sometime ago I listed a 20 year something sailboat that was a major brand, super clean, and immediately the listing started attracting potential buyers.

One of the sticking points, however, was the fact that the engine hours were “unknown”.  The current seller was maybe the 4th owner of the boat.  The hour meter read “72”, so whatever caused that meter to stop working happened long ago.

Everything else about the boat was great for her age.  So if you come across this situation as a buyer, or as a seller or even a broker, what is the best course of action?

For me, it all depends on the condition of the rest of the boat.  If you’ve been around boats for awhile, you know instantly whether a boat has been loved or not.  If there’s little to no evidence of that, then walk.  However in this case, the boat looked great, had obviously been cared for, and the engine, at least on the outside, looked clean.  No leaks in the pan below it, hoses and belts seemed in good shape, etc.

So if you want to proceed, the steps to veteran boaters are obvious, but it doesn’t hurt to review them here.  And if you’re a boating newbie, hopefully you find this helpful.

A.  Review the maintenance history. In the case of this boat, the owner had a pretty good accounting of the work that had been done on the engine.

There were records of oil changes, coolant flushes, impeller replacements, and other routine services going back a few years.  This is a good sign that there’s been diligent upkeep of the engine.

Perhaps most importantly, see if there have been oil sample tests in the recent past.  One sample test, while helpful, is just a data point.  Multiple tests, even just 2 seasons in a row, can identify patterns that are much more meaningful. If it’s the spring, first find out if the oil was changed last fall. If it has, then taking an oil sample now won’t be helpful.  From my experience, you need at least 25 hours on a diesel engine, or 20 hours on a gas engine, before an oil sample can be viable.

Things to focus on in evaluating oil samples:

-Metals.  Iron, Aluminum, Chromium, Copper. Trends of increasing levels may indicate wear in various engine components.

-Oil Properties.  Viscosity, Base Number, Acid number, increasing values can indicate contaminants or degradation.

-Contaminants. Water, Fuel, Coolant, Soot, etc. The presence of these can indicate corrosion, leaks, poor combustion, etc.

If the owner lacks maintenance records, that’s a big red flag and I would probably walk. If they have good records but the oils sample tests show a trend of elevated elements per above, I’d probably walk.

B.  Evaluate engine type and usage patterns. Engine types - diesel v. gasoline.  Now in sailboats, this won’t apply as (as far as I know) they all use diesel engines. But if you’re evaluating a power boat, gas engines are a popular choice.  Diesel engines are known for their longevity, often exceeding 5000 hours or more with proper maintenance.  Gas engines have a shorter lifespan, averaging around 1500 hours before major overhauls.  If it’s a gas engine you’re looking at, my advice is to be even more careful.

Usage patterns.  Engines that have been used regularly and maintained appropriately tend to be more reliable than those left idle for extended periods. Prolonged inactivity can lead to internal corrosion and other issues. Try to find out what you can about the usage history of the boat.  You’ll probably only get info from the current owner, but more recent usage is better than not knowing.

C.  If you decide to make an offer and go to survey, consider doing a separate engine survey.  Find a surveyor or mechanic who has expertise in the manufacturer of the boat’s engine. If they can survey the whole boat, even better.  During survey, in addition to the typical stuff (Visual inspections, observing engine under load, etc) consider having them do a compression test as well.

All of these assessments can reveal more about the engine’s condition than hour readings alone. 

Lastly, consider the broader context.  Remember a boat’s value isn’t solely determined by engine hours.  Accomodations?  Layout?  Condition of rigging (sailboat) or running gear (power boat).  Does your partner love the boat (this closes or scuttles more deals than anything else FYI).  Take everything into consideration.  In this case, one of the buyers loved everything else about the boat and after the survey revealed no issues, they moved ahead.