The point setting on a 30hp Chrysler outboard would be .020in. if you are refiling your old points they should be set at .018in
The point gap for the 50 hp Johnson outboard is set at .020".
The magneto point gap on a 2hp Yamaha outboard is 0.35mm, or 0.014".
.030
The recommended plug gap for the 1972 model, 20 hp Johnson outboard is .030 in.
.020in
0.020 in.
.020
.030" Champion L4J (L86C) or NGK BR6HS
0.030
The points gap on a Merc 40 4hp is .020
0.020 for the points gap, spark plug gap 0.028 -0.033