Volvo TAMD 74P-B turbo siezed

[Jimgugger]

Hi all. I have a 2002 Volvo Penta 74p-B in my Silverton 43MY. The boat sat for quite a while before I bought it but worked fine for my trial runs and a few other short runs but then I started getting black smoke from the starboard engine and it wouldn't go above 1300 RPM. A mechanic took the exhaust side of the turbocharger (which I believe isn't very old) off and it is full of black gunk. He has quoted me $9000 just for a new turbo. My research pulled up pricing anywhere from 1500 to 4000 but unless I have to I don't want to buy a new one. Does anyone have any advice on if this can be just cleaned out and is there something I can do to prevent this in the future? I'm guessing this has to be partly due to lack of use but maybe the engine has deeper issues? Thanks for any responses.