Kawasaki engine dating

[Wayne Offiler]

Just picked up a 10-year old Skag 48 as a back-up mower. the 14 hp Kawa engine runs very well and I suspect it is a replacement. Does anyone know how to interpret engine codes so I can determine what year it is?
BTW: This engine is marked: FC420V-AS12 and FC420V153101.
Thanks!