Under contract - 2003 Neptunus 56 w/ cat 3406e - top speed/rpm issue

Note that the word used was "overhauled" and we used the "rebuilt" word. However, overhaul means different things to different people and I doubt seriously it was a rebuild, plus it was not done by a CAT dealer, even though by someone who claims to specialize in CAT.

Reality is we don't know what was done. I could change three parts and claim I overhauled. No one saw the exact work done.

Some may, this one didn't, but we don't even know what they claimed to have done.

That invoice may only have labor and 10 rattle cans of paint..........hence no documentation, too embarrasing.

Someone will fall in love with it and let emotion rule their decision, not glaring facts

I don't get it. You "bought" a boat in June and you walked away? How does that work?

200 hours over the 1000 hour recommended service, not ideal but is there a story about why that was delayed or not performed? Possibly there are boat owners that don't know the maintenance schedules.

I am all for routine maintenance and regular service, I just am wondering how many boats in this age and size are maintained to a tee. I feel like you may be looking for a long time. Nothing wrong with that at all, I am just thinking that a 50-60 foot twenty year old boat with a perfect maintenance record will be scarce regardless of inventory.

I wanted to add one thing to this discussion of max RPM and performance. Once you've determined that a boat's engines reach rated RPM plus some extra (typically 50-100 RPM up to a governed maximum), then you get into performance issues. There you check to see if you're reaching 100% load, assuming you have the ability to do so. If it isn't, then you know you have another issue. It's only at this point that you look at propellors and pitch. Often propellors are the first thing people look at. They should be the last, after you determine the engine is performing right. That's why I kept telling the OP we weren't discussing speed, until Max RPM was achieved. The goal is really then to hit 100% of Rated RPM with 100% load. There is actually a decent article on a site that may be censored here, but, if so, I'll put in different language.

https://boattest.com/article/full-t...dgw&utm_content=201866710&utm_source=hs_email

All standard stuff except you did not purchase the boat. Being cautious is good. My insight is not nearly as valuable as RER, mapism and Pascal to be sure.

I don't want you to buy a boat that you feel your due diligence is telling you to walk away from but you seem to have an idea of what will or should be available. Why not spell that out before offer, haul out, survey, sea trial...

Paying for your time and haul outs and broker's time and efforts are fine, but perhaps before the haul out and survey be sure to get all the service records and maintenance interval logs before all of that if you are not willing to rely on survey and fluid analysis and sea trial.

I'd say 8 out of 10 yachts that age have some sort of neglected maintenance if not lots. You look at the oil samples, if good, figure out what it costs to get the motors up to speed on maintenance and negotiate. It's like MAN's 1000 hour service is 1000 hours or 2 years, nobody does it every 2 years if they're out of warranty and quite frankly I don't believe it's necessary and neither do many MAN mechanics. NOW, the CAT aftercoolers changed every 6 hours I do believe is necessary.

Not really, of ALL of the MAN owners I know, 90% do the 1000 hour service every 1000 hours regardless of years and rarely if ever have an issue as long as it hasn't been 10 years. I've seen a handful or two of CATS need a major due to a leaking aftercooler.

You said changed every 6 hours.

LOLOLOL didn't even notice that until OB pointed it out. Hey, I like my aftercoolers shiny and clean for maximum performance. hahaha...... should be 6 years.