Re: early 80's 70 HP Johnson
I have a 1980 70hp with similar symptom. I started with the fuel system. It takes time to go through it from the fuel, fuel tank... all the way to the carbs. Now I see that I have an intermittent weak spark on #2, or sometimes #2 & #3 cylinders. It takes time, patience, and very methodical troubleshooting. I've eliminated the plugs, coils, powerpak, and loose connections. Now I need to know how to determine whether to buy a stator coil or sensor coil. Both are pricey. Good luck to you. Get a good manual.
