Well, we decided to ask the Onan agent in Levkas to have a look at our problem ( which I am convinced is a sticky governor mechanism, having the effect of failing to increase the flow of fuel when load comes on ). The guy said he had been servicing Onans since the 1970's. After seeing the problem for himself and conferring with the main agent in Athens he pronounced that the problem was that Amel had designed the exhaust outlet too close to the water line, thus creating resistance......
Needless to say, he is now off the boat. I suppose that I will have to pay him something!
I am ordering the Engine Service Manual. The Service Manual says that for Over/Underspeed " check for internal binding of the governor mechanism and repair as necessary " The very helpful Onan agent I have also spoken to in the UK says that repair is pretty self explanatory from the Manual. I hope so!
Ian and Judy, Pen Azen, SM 302, Levkas, Greece