Lightfour heavy duty lower unit Home › Forum › Ask A Member › Lightfour heavy duty lower unit This topic contains 0 replies, has 1 voice, and was last updated by oldboatmotors 1 month ago. Viewing 1 post (of 1 total) oldboatmotorsUS Member - 1 YearReplies: 8Topics: 3 January 21, 2019 at 6:59 pm #164221 Were the gears in the heavy duty Lightfour lower unit made “in house” or were they outsourced? The motor is a WW2 lightfour. Attachments:You must be logged in to access attached files. Viewing 1 post (of 1 total) You must be logged in to reply to this topic.