Found low hour, 38, boat in Florida. 2010 model with inboard merc. Looking at pictures, it seems to be stored at marinemax indoors. Does this mean the boat would be flushed each time by marina as normal practice?
You would have to ask them if they did it. But I wouldn't expect proof to be available unless they kept some sort of records with a checklist etc.....(don't count on it)
The only way to tell if an engine was 'flushed' would be to know how old the manifolds, block and risers are, and do a visual inspection of the cooling passages. That would mean pulling the risers, intake manifold, circulating pump etc, and looking.
Only then could an experienced "surveyor" estimate the life remaining in the raw water areas (from the amount of rust buildup) . That person might also be able to "guestimate" if the engine + associated components were flushed with fresh water and/or if salt-away (or equiv) was used.....
I am not sure if they do that. It would be a pretty big job to pull enough cooling parts off the engine.
If the boat has closed cooling, it would simplify everything and make the risers the only problem area (then I would only want to know how old they are)
With open cooling, I would still want to know how old the risers and manifolds are. If you (or the inspector) pulled the risers and looked, you could get a pretty good idea how clogged the block might be........
Good luck,
Rick