Question

I have a 2002 Sabreline 36 Flybridge Cruiser with twin Yanmar 370 engines. During a recent cruise, I noted that a lot of gray smoke was collecting a couple hundred feet behind the boat while traveling at about 18 knots. The next day while on a 10 mile leg, I increased the speed to 18 and black smoke came billowing out of both exhausts. We reduced speed to about 10 knots and made it to a yard. They determined that the starboard exhaust had been leaking sea water which had sprayed around the engine room causing corrosion in a number of places, They removed both Turbo injecter pumps, found corrosion and even water in there, and sent them to Yanmar distributor in MA for rebuild, thinking that over-fueling chambers was caused by them. Their mechanic said that all the water in engine room caused water vapor to be drawn into both turbos throgh air intakes. It did not solve the problem. Engines won't exceed 2000 rpm and black smoke still there at higher speed. Any ideas?