Mack Boring runs the type of course you are interested in completing. I attended the two day in shop course. While it is accomplished on Yanmar engines (that's what they sell and service), an engine is an engine. You have to practice on something. They took us through most maintenance items: adjusting belts, changing fluids and filters, rebuilding
pumps and cooling systems, bleeding
fuel lines, changing ejectors and torquing the head, etc. Once you take the course, you should be equipped for routine maintenance and emergency
repairs if you have a maintenance manual and a good spares kit on board. You should check the current course items, but I doubt if they have changed much.
They also give you recommendations on required tools and spares. Great course. I still hire out most of my maintenance, but I am confident that I can diagnose and fix most common problems if I have too. It's pretty to neat disassemble an engine and cooling system, put it back together and having it crank and run properly. A real confidence builder.