Ken,
I realize that you posted this a few months ago, but I needed to check on a couple of items. I have installed a oil change system on our Yanmar 2QM15 that has significantly reduced the stress and strain of changing oil. Our boat is a C&C 32 with frontal access to the engine as well as space under the engine. Upon haul out, we removed the oil pan - bottom plate - of the engine. There is a "dummy" plug in one of the corners which I had drilled out, threaded and a spring loaded L shaped nipple valve (this a description of the item - it may be called something else) screwed in. I then fitted a short piece of plastic tubing over the open end. When I want to change oil, I slide tubing into a milk carton, turn the valve to open and let the oil run. I usually leave it over night to let it drain, turn off the valve, cap the carton and recycle the oil. We have used this system for four season without any problems. The cost of the tool and die work was minimal - under $75 (Wisconsin prices - may be higher in the East) The value of the system doesn't have price. If you have any questions, please contact me.
Stephen
French Vanilla