i have an 18 hp (?) evinrude. s/n is 15020 10044. # on freeze plug is 15020 08212. # on flywheel is E O 304736. anyone know year, model and hp? Also, engine quit while out on lake (after shutting off to cast for a while, could not restart). was able to restart, but would not remain running longer than 30 seconds or so. now unable to start at all. any suggestions?