I'm looking at a boat set up with 525' and about 240 salt water hours. It was before thought to have less hours. The boat was taken care of and well flushed after every use. Also has new headers about 60 hours ago. Should I be worried and running from this?

How about the top ends? Have the heads been gone through? If not they will need it soon so figure that into your offering price.

No...The top ends have not been gone through. Let me add that the boat is an '05 so it has had little use.

It's about time for a top end regardless. My headers went at 185 hours too even though I was good about flushing it. Had my top end done then at that time as the water hurt the valves.

Have the motors put on the merc scanner , this way you can see how many of the 240 hours are at WOT, versus idle or 3100 rpms. Those motors can go 350- 400 hours if they havent had the $hit run out of them before you need to do valves and springs etc etc.

I have more than 350 hours on my 525's with zero problems
changed the headers at 300 hours just to be safe
the boat lives in the salt. i also flush after each use.

My boat is a 06 and most of its use is cruising around the harbor but last month i did a 200 mile run to Newport and back so as long as it's taken care of i wouldn't be worried