Hello,
that's right, the reason : older Honda ref. was like that, e.g. BF5A = BF50 (5hp), this link :
BF5A BF50 service workshop repair manual
and I guess that's the same about the BF50L = BF5L (5hp)
check if searching "BF5" you have some infos and parts from this page :
Honda outboard...