distributors in Jacksonville
, FL, with whom I have no affiliation, had a complete 3 cylinder rebuilt Marine Yanmar diesel
for my 9KW Kohler Generator
for $4,000 delivered to Orlando (they sell on eBay under some other name too). R&R was $2,000 (had to pull up floor iin my ACMY) if that means anything.
I would get a second opinion and qet a quote on how much just to R&R the engine, then shop some prices on remans, since a local rebuild
could take forever and the estimate is just that. Why $10k for a 'repower'? how much of that is the engine and how much is labor? A Major Overhaul
kit from Yanmar is around $600 plus machine shop work and general labor should bring a local rebuild in closer to $2,500 plus R&R I would think, but your options may be limited down there as to qualified mechanics, I don't know. I would call Yanmar and see who is the authorized warranty shop there, they may be a good second opinion, that's how I found the guy I used; he was quite good actually.
Good Luck, hang in.