Help on buying a boat with 610 MAN:s

in m experience with my 10 cylinder 820 mans have been exceptional. I run an average of 125 recreational hours 1800 rpm is my usually run. for 19 years. sometimes I have to add 10 oz of coolant.... One pint of oil over the season?

Agreed, once you find a good one, hang on! I go to Mystic CT from Oyster Bay on LI for mine. Parts are more expensive also.

In my part of the world, we are the "out of town" you bring them from. lol

There is a good Man dealer in his town. RD something or other. Yes, they're good engines. The hours should be fine and should get 6,000 hours out of them. Have them surveyed by a MAN dealer before buying. They're like 92 detroits though. Running them easy does NO favors for them. They don't have a lot of torque compared to CATS and they like to run 1950+ RPM'S at cruise when they're in more boost and more HP and not relying on torque as much in most boats unless they're in a light and fast boat, then they don't mind running less RPM's. What kills any engine is a swinging load factor/rpm and boat speed at the same throttle setting. I always run MANS 80% load and that is what the head engineers from MAN North America told me when I spent a week with them doing 7 days of seatrials so they could program the master fuel curves and other computer parameters for the entire line etc. for the new Common Rails at the time. Balancing acceleration, versus smoke etc.

Well, if the conditions hold for tomorrow, we're going to have a convoy of MAN's, enjoying the one good day for boating before things turn negative again.

Just we have a couple of boats with them and two of our friends do as well. So probably will take two to four of the boats and go play. A quick run somewhere. Maybe Marathon or even Key West for lunch.

Had these engines, ran good. These engines have a weird raw water pump...has two impellers...one large and one smaller. Change the impellers on schedule or every year. The smaller impeller will not last as long as the larger one, always carry spares. Have the owner furnish you the quote for the 1000hr. and what they are going to service. They will load up after running slow so run for long periods...so run at fast cruise to clean them up. Like Capt J said, don't be afraid to run them 1950 at cruise. Sold ours to a friend and he just had to replace one of the engine alarm controls for about $3500, rebuild turbos, and full 1000hr....parts are expensive. Seatrial again after 1000 hr. service with Man mechanic before accepting.

We have 2876 - 700 Hp
Are the 610 Hp an early derivative of this 12 L straight 6 ?
If so they are bomb proof .
I run mine at 1760rmp in a 15/17 ton Itama .
As said ^^^ with MMDS you can access the load % .I try to do a long run under 80 % too which equates to over 30 knots in my boat .

I think the secret to longevity or turned around low running costs is not overloading .

Buts that’s partly down to the builder selection of the right tool ( engine ) for the application, not the actual engine brand .

So while they compliment Itama , who knows if they compliment the OP,s prospective boat ??

Too many boats are powered “ on the limit “
An extra 1lb of stores or 0.001 micron of fowling - you get the idea ! - and they are running over 95 % maybe 100 % all to often = knackered perfectly good engines

They are v easy to work on and the engineering is as expected from the Germans .Base block is used in road trucks and railway carriages.

Very happy ownership experience after coming from Volvo Penta .