So the voyage of a Sea Scout donation of an above mentioned Hunter has a new wrinkle that I am hopefully looking for some guidance on. I was bringing her up the Chesapeake Bay this past Saturday and Sunday. Had a successful motor all day Saturday, stopped for the night, got up next morning continued to motor, had been running the engine for about 6 hours when the engine appeared to throttle down without touching the throttle and a little black smoke was seen. I keep going (at this point at the Bay Bridge) and am able to limp my way home for an additional 5 hours with the throttling down continuing to occur to the point that it is running just over idle speed (no idea on RPM because tachometer does not work). As I am making my way up the river the black smoke is getting more voluminous and I look back to see a trail of unburned diesel fuel on the water. So I actually touch the throttle at this point and pull back on it to actually align the throttle position with what I hear as the Idle speed and the trail of unburned diesel fuel stops, but I am still limping along. So I have an eventful landing with basically no propulsion, she is tied up in the slip, and now won't start since Sunday. I have been reading and researching and one article I read says "no throttle response and black smoke" is NOT a fuel issue. Another article says it is probably a clogged mixing elbox. Another article says a clogged water intake into the mixing elbow. Other articles say, getting the mixing elbow off is a real pain in the butt. I know no one call foresee what the problem is, but before I start ripping things apart, making the issue worse (although how can it get worse if the engine won't start), breaking things, or the like, I was hoping to get some sort of confirmation or advice or guidance that I need to maybe go in a particular direction. Thank you in advance for any advice. PS: The starboard rear quarter of the hull (behind the exhaust) is black with soot.