That motor has a Bendix-Scintilla magneto. Expect to find the coil either cracked or turned to goo. oldoutboardjim@hotmail.com is the man for new ones.
Just got two Bendix Scintilla coils from oldoutboardjim for my Chris Craft 5 hp. Put them in last week and it's up and running. Good guy to deal with and fast shipping.
Original plug was a Champion #7. Replaced by Champion D-16. That information current as of 9 years ago. But a parts house should be able to confirm or update from that. BTW, that is an 18MM thread.
OK... So I had to order that plug... However, I took a plug that I currently had, attached it to the lead, pulled the rope, and I had fire! Does that mean that mean the magneto is good? If so then it's on to the carb which I will be cleaning out while waiting on the plug to arrive. The guy I bought it from showed me a video of it pushing him and his daughter on a small Jon boat 3 years ago so I'm hoping there isn't much else to do with it!
Just because you have fire on the stand does NOT mean you'll have fire 3 miles from shore. As Frank noted, check that coil. Those old Bendix Scintilla coils are noted for cracking with age. You could very easily have spark now with a cracked coil, but as it warm up, gets exposed to humidity, etc., that spark will weaken. The points are no longer available, though, so be VERY careful with them.
OK... That's noted. However, it is running in the barrel! So at least that. Now that I consider it worth working on I'll check the coils and carb. https://youtu.be/vgqCBoSb_-0
Just got two Bendix Scintilla coils from oldoutboardjim for my Chris Craft 5 hp. Put them in last week and it's up and running. Good guy to deal with and fast shipping.