I just purchased a 1991 15hp johnson (according to the owner) but I can't find a serial number anywhere. I have a 1987 9.9 evinrude and the serial number was worn off the plate (like the 15hp) but I found in on what seems to be a freeze plug in the head. Now on the 15 has the same freeze plug and location, but doesn't have the serial number stamped in it. Where else can I look to find a serial number?
