Back in my Parasail Boats days we could get 3000 to 4000 thousand hours out of the 330 hp 454s.And they were ran hard and put away wet.

Problem is most go fast guys are Newbies and don't know a phuckin thang about engines. It's not the runnun the chit out of them that kills them it is the not knowing when they need a little love and kiss to continue the relationship that they miss.

I have 760 hrs on 496s, 375 mags motors run perfect.
Change oil every 30 hrs and dont build them.

I think the key to longevity engine life is respect-maintance and keeping it in stock form. My opinion is extreme performance mods blowers-turbos make the engine disposible.

Offshores are driven at higher rates of speed so when the guy in the cruiser takes 3 hours to hit destination we get there in 1.

Typically motors in offshores don't wear out, they have catastrophic failures from, overheating, blown head gaskets, eating valves, and so on.

I run my 6.2's @ 2800-3200 RPM whenever we are driving the boat, sometimes I will open it up but that is not often.

Why the low hours?

easy answer - Boat engines are subjected to continuous loads not seen by other forms of transportation. If you were to compare to an auto it would require the equivalent of towing a heavy trailer uphill with the trailer brakes dragging- the entire trip.

It isn't unheard of to see a high hours engine as you've seen in these posts, but it isn't common for sure.

Uncle Dave

another consideration is the fact that most of us have an ultimate desire to go faster... thats what brings us to this arena of boating. the need for speed typically ends up leading to the desire of more power (new engines) or a bigger boat with bigger engines (selling boat with lower hours)

Thanks for the input guys. So would you mess with your stock 502 mag with 440 hours or leave it alone? If you were to freshen it what does that entail and what does it cost?

My 05 525's have 330 hrs, still feel great. They are never abused and get Merc 25W-40 every 25 hrs.

I have 320 on my HP500EFI's, no change. I did rebuild the heads around 280 hours.

So what is the record for HP500/efi/525 NA?