I repowered with the 3YM30 two years ago and have over 500 hours. It is very quiet, does not smoke or smell and always starts immediately. Not a single problem so far. In this 19,000 lb boat we cruise at 6+ kt at about 2750 RPM. The gear is 2.62:1 with a 3-blade 16X11 prop.
Never sail closer to the wind in degrees than your age