I’ve generally heard good things about the Johnson 9.9 motors. They were made in Peterborough to the same design from the 1950s. I was thrilled when the motor started before the season as I didn’t have to spend money on it, or time trouble shooting and fixing.
For the last couple of weeks it was giving me trouble – cutting out, hard starting. Finally it refused to start at all. I searched forums, read manuals, sniffed, poked it with a multimeter – decided it must be electrical. I pulled the plugs and yes it had spark – or did it? – hard to tell – a very weak spark, sometimes no spark? There is fuel – but I pulled the carb anyway to check and clean – squeaky clean.
I was about to order a new power pack as the more I tested it the more it seemed like there was intermittent or weak spark. I decided to check the stop button and discovered that when I disconnected it – the motor burst to life – then I touched the loose wire and got a good shock – ah ha found the problem! Inside the button was about 1cc of brown water. The contacts were just floating/shorting. Problem solved.
All this done bobbing on the edge of my dinghy, but at least my feet sat in the cool water – not a bad office.
With new plugs, a dose of Seafoam and a dry stop button and the motor positively purrs – well as close to it as it gets for a ’81.