Gear case housing question

[Taney37]

Rebuilding a 1968 RDSL-30-C 40 HP gearcase including all bearings, seals and water pump. When looking into the water inlet from the exterior of the housing there appears to be a small passage. I thought it was just plugged and used a small drill bit by hand but it is not just clogged. Not sure if this is an actual small passage into the second unused water tube hole furthest from the water pump. Read the tech notes from MarineEngine stating the unused water tube hole farthest from the pump should be plugged and sealed but haven't found any reference to the possible hole shown in the picture. Could possibly be a drain bleed for the plugged and unused rear water tube hole? Would like to know if it is a through hole and needs to be unclogged prior to reassembling the lower unit. Thanks in advance for any help on this issue.

 

[racerone]

I believe you need to do some more looking into what you have here.-----That hole in that plug means nothing !-------Post pictures of your water pump and all the copper tubing here.----Also the 2 sides of the gear case.---It may not be a 1968 gearcase that you have.

 

[F_R]

Yeah, more info needed. There were a couple of versions of that inlet system.

 

[Taney37]

Thanks for the responses. 3 pics of gearcase housing and skeg. The previous owner did say the lower unit was replaced, not sure how to identify year as I only see casting numbers on each piece. (Skeg 302520 & housing 314328,) The motor was running great but wanted to replace impeller and seals plus check bearings. Am ordering water tubes, were replaced with same diameter plastic tubing sometime in the past. Oh well, the motor is 50+ years old! But it pushes my 1968 16' Alumacraft boat OK and is the original motor for the boat.

 

[racerone]

Just stop guessing.-----Use the 1969 / 1970 parts manual and the 1969 / 1970 water pump tubes and parts !!----Do not run the motor unless you are sure you have the correct parts.------Or hurry to a competent shop with an " old time / greyhaired mechanic !!