This chart is furnished as a guide. JOHNSON, EVINRUDE, & OMC SEA DRIVE SPARK PLUG CHARTS --Mastertech Marine-- HOME PARTS LISTINGS PARTS LISTINGS PARTS LISTINGS Wondering "Where-'n-'Ell" to get great parts for your outboard? //-->. Your email address will not be published. Made of alumina silicate in its ceramic insulator, copper core and is triple sealed to help dissipate the heat. If the electrodes are broken off or flattened, it is likely that the wrong spark plugs are installed. . From leisure boats and jet skis to personal watercraft (PWC) for professional purposes, drivers depend on a reliable engine when going out on the sea. Healthy marine spark plugs are essential for your boat engines performance and longevity. If you would like to check the gap, you can do so with a gap gauge. PUT SOME FIRE ON THE WATER. Stock No. - Periodically, we'll send you tech tips, DIYs and boating information. Perform this exam as routine maintenance, even when the engine is running fine. Without removing lower cowl ? ,