Thre is no gap on the plug as it a surface fire plug.
The spark plugs on a 1988 model, 70hp Johnson outboard, should be gapped to .030in.
in the box just above your top spark plug (four flat head screws hold it in)
0.035 is the gap size
1988
yes but they are a problematic motor
1988-89
9.9 force
50:1
23 years old made in 1988
The listed dry weight for a 1988 model, 70 hp Mercury outboard is 265 lbs.
The dry weight for a 1988 model, 20 hp Mercury outboard is 105 lbs.
The dry weight of a 1988 model, 70hp Yamaha is 233 lbs.