Glad to hear that it was simply a prop cleaning issue which we assumed would be the case. You will love that engine we're sure as it is a good match to the SM. We have just discovered that none of our recent responses to this forum got sent from the new mobile phone so will answer your previous question again about what RPM's we usually run at.
When motor sailing we tend to run the motor at approx 1500 RPM's and 1700 - 1800 when motoring long range. When on a tight schedule we may run at 2200 - 2400 but seldom over this other than an occasional burst for 5 mins or so every hour at 3000 - 3300 or max depending on prop and hull cleanliness. Generally we tend to average about 6.8kts - 7.5kts but can do 9.5 when everything is clean and slippery. The good thing about that motor is the extended motoring range you get as the 75 HP Yanmar is extremely frugal but also simple to maintain and wonderfully reliable.
Colin & Lauren Streeter
Island Pearl II, Amel 53 #332