IMHO there's hours and hours. There's hours put on by a diligent owner who never let the engine overheat, changed the oil and filters, and took good care of things. Then there are hours put on by owners who ran it hard, overheated, never changed fluids, etc.
For me, yes, I'd rather have a working tach with a number I believe in, but characterizing the seller's diligence in maintenance is the most important factor when deciding to sign. If the seller is in the diligent category, chances are pretty good the tach hasn't been tampered with. And if there's no tach, unless the owner can show me a very complete log or some other system they are using, how did they know when it's time for an oil change?
Yea, so as a buyer, I have spend almost as much time surveying the previous owner as the boat
Usually, the overall condition of things behind floor panels and other out of sight locations tells the story right away.
YMMV.
For me, yes, I'd rather have a working tach with a number I believe in, but characterizing the seller's diligence in maintenance is the most important factor when deciding to sign. If the seller is in the diligent category, chances are pretty good the tach hasn't been tampered with. And if there's no tach, unless the owner can show me a very complete log or some other system they are using, how did they know when it's time for an oil change?
Yea, so as a buyer, I have spend almost as much time surveying the previous owner as the boat
YMMV.