1995 Mariner Mercury Outboards Service Manual 50HP 4-Stroke, Page 31Get this manual
Resistance Tests (cont SPARK PLUG CAP REMOVAL
NOTE: High tension cables must have spark plug cap removed before testingCap contains 5k ohm resistor
SPARK PLUG CAP RESISTOR TEST
IMPORTANT: To remove spark plug cap from high tension leads, turn cap counterclockwise while applying slight outward pressureDO NOT PULL HARD or lead may be damagedTo install cap, turn cap clockwise threading cap onto high tension lead