The boat goes in the water tomorrow (crane day!). Woohoo!
But this presented a minor problem with the gas engine removed from the lower unit (transmission).
Namely: sinking quickly to the bottom of the harbour.
The problem is that with the ICE removed, there is an open passage up through the gear case (below the hull) into the engine compartment to feed cooling water to the ICE. And since the
top of the lower unit (inside the boat) is
below the waterline, you can see where this would ultimately lead. Swimming with the fishies.
(Incidentally, this is an inherently bad design. If you ever have to change the water pump impeller - not an uncommon thing to do on marine engines - you first have to remove the engine from the lower unit to get to it. Which suddenly permits water to flood into the boat. Which means of course this boat has to be lifted out of the water to replace the water pump impeller. Clearly not designed by Germans.)
So my first task was sealing up that water passage.
I removed a plastic screen from the water intake, shaped a plastic plug to fit the opening and then hammered it in. Then I epoxied over the plug (several layers):
After the epoxy cured, I slathered a liberal coating of silicone over top...
To be extra safe, I will also be sealing up the
top of the cooling water passage, inside the engine compartment. That's my task for this evening.
And here's a view of the top of the lower unit, showing the input shaft that I'll be mating to the electric motor...
Edit: I'll also be removing the impeller (which is mounted directly on the input shaft), since we don't want that spinning merrily away in a dry water pump housing.
FYI, the cooling water passage is visible at about the 8 o'clock position from the input shaft.