Hi,<br /><br />Don't know of a b13b although there was a b12a, which was 10hp.<br /><br />Try Tohatsus web site (unless you can read japanese, remember to change it to english), Find the gallery page, and it shows their old brochures. If you cannot find it there email them, they are very helpful, sent me some useful info on my 1979 5hp tohatsu.
the b13b was the precursor to the m8a, and shared many parts with the 10hp models: m9.8a / b18d , and the 12hp models m12a / b18c
the b13b lacked thermostat and lighting coil
