Merc 500 colonoscopy

Hello! So I recently changed an impeller on my 1964 Merc 500 but it seems as though there is no water coming out of the pee hole. I've tried sticking a wire in there and it feels like there a solid something blocking the wire. I can only make it in there about a 1/4" when trying from the pee hole end.

I've stuck my endoscope up the copper pipe that brings water from the water pump to the block. I've attached a video of my findings.

I did notice that there is water flowing about 3/4 of the way up the copper pipe, and when I remove the lower unit the water comes back down the copper pipe going up to the block. The water is exiting the motor from somewhere it's not supposed to be exiting. The block seems nice and cool when running the motor so I'm thinking the water is making it into the block regardless of what the pee hole is doing.


The blockage looks metallic, there is also a black thingy on the side that may be old impeller pieces or just crap in general. I don't know if the gear I'm in affects if the pee hole functions or not? I'm under the impression that the pee hole should function regardless of the gear the boat is in.

Can anyone help me out here?

Thanks!

Here is more video. The first one is me hooking up a garden hose directly to the copper pipe. I realize I may not be getting full water pressure to the head so this was just a test.


The second video is the motor back together with the earmuffs on. Same result. No water from the pee hole but the block feels cold to the touch, even under load.

Also one more question: Where would I install a water pressure gauge on this outboard? If anyone know off-hand I would love to know.

Some have a tapped hole in the water jacket cover (where the plugs go through).

I drill and tap the top rear of the block for my own Tell Tale. Easy to do.

Jeff