Our 1976 85 HP Johnson (same basic engine) shows 0.040" in the Owners Manual and original Johnson Factory Service Manual, but the Seloc manual says 0.030". I asked the mechanic, and he said that OMC revised the gap spec due to decreased plug life at the larger gap, but that the engine will actually run slightly better at the forty thou gap.
the --.030--i have found,as well,as BRP/omc...to be a better gap...at the 40,they tend to burn up plugs fast...has operation is about the same,but IDLE,characteristics,are greatly improved......go w the 30.
