Love the engine, reasonably quiet and reliable... some say under-powered for our Sparkman and Stephens 35 (a custom built cold-molded IOR 3/4 tonner), but with the right prop (good fortune had us inherit a Max Prop) and pitch we produce a good turn of speed with plenty of RPM left over.
The only bug bear is that for our installation, to service the freshwater pump, one must remove the entire assembly/mounting flange since the pump faceplate faces aft and we cannot quite get in there with our hands/tools.
Hint, if you get one, the foam material used for the air intake filter/silencer eventually distintgrates and ends up being suched through the engine ... not likely a problem, but messy.
Other hint, the transmission should not be overfilled as there will be glazing of the transmission cones and subsequent slip.
If you get a Yanmar, here is a good link (that you likely have)...