I have a 1988 Mercury 25 2 Stroke (SN B267056) and the current spark plugs that's in it is an NGK BUHW (gapless style), but I have seen it listed online as also taking an NGK BP8H-N-10 (extended tip).<br /><br />I think either one will work, but I'm wondering what it came from the factory with.<br /><br />If it is the normal style plug, I'd also be curious as to the factory gap setting. <br /><br />Thanks for any advice!