Plug Speedo Tube in Transom

Hi All,
I've been chasing a minor leak at the transom and have determined that where the pitot tube comes through the transom is the culprit as shown in the image. It appears that the inner portion of this is MIA but I would simply like to plug the whole as I use my GPS for speed reading.
Has anyone plugged this before? Would it be better to plug it from the outside or inside? Any advice would be appreciated.
Thanks!

That looks nasty. I have same question, but my drive is already off...

There is a barbed fitting which is screwed into the transom assembly. Best method is remove the barb and install an 1/8 NPT fitting

Thanks AllDodge! My drive is off, so I'll just remove the gimbal bell housing and take care of that issue.

gustaf said:

Thanks AllDodge! My drive is off, so I'll just remove the gimbal bell housing and take care of that issue.

Click to expand...

The place showing is on the inside of the boat, its just below the steering arm and to the starboard of the sender wires

Sorry, AllDodge, are you suggesting that this should be repaired from inside the boat rather than from the outside? I was thinking that the better place to plug it would be from the outside to ensure that any water cannot get beyond there. Doing it from the inside would mean that the transom itself could get wet and ultimately cause rot issues.

The speed-o fitting is part of the gimbal housing (part of the transom assembly), and there is a brass fitting (22-816594A1) which screws into the housing from the inside (pointing finger). The speed-o tube attaches to the fitting inside by using a thin clamp. Basically the hose is pushed on and clamped, then the hose is feed thru the housing from the inside and the fitting is screwed into the housing.

So to seal off from the out side you either need to plug the hose and hose it does come loose later, or plug the hole with something like 5200. The easy way (hard to get to) is to remove the inside barb fitting and install a 1/8 NPT plug, or remove the entire fitting and plug with a 1/4 NPT plug.

This is the fitting without the hose installed