Interesting thread. I noted olcah comment about the 1954 model electric start powerhead having a different casting, i.e., threaded studs, to allow for the starter bracket. I had a similar experience with what I thought would be an easy electric start conversion with a Mercury Mark 25, I went into that project with my eyes wide shut! The 2 years, 1955, 1956, Mercury produced that electric start model it also had a dedicated powerhead with 4 threaded studs to allow for the starter bracket. For kicks and giggles I have considered drilling and tapping the 4 studs in a standard Mercury Mark 25 powerhead for an electric start conversion. I love the convenience of electric starting. I’ve done several 1957/1958 J/E 18hp conversions and they couldn’t be easier. It was interesting reading today about the early, (1954), OMC history of electric starting.
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