linemangreen
Active member
Has anyone had a 2002 4-stroke 225 yamaha crack a spark plug . The motor wasn't running great but once you took it over 900 rpms it cleaned up . I pulled all the plugs and one was cracked down the center and fouled . So i replaced it and ran the boat for 15 mins and checked the new one and it was also cracked . The bottom of the plug is fine its not being hit . Please HELP ???