Re: V4 cooling schematic?

[Don]

Yeah, you don’t want to crack that plastic for sure….Maybe a razor knife gently inserted into the gasket surface? It is probably best to just replace that vernatherm while you are inside the box, make sure the check valve is clear of debris and working properly….
Frank pointed out a good spot for the overboard indicator tap. I seem to remember that your control box only has a "hot light", instead of the "hot horn". You might consider adding the hot horn inside the box if possible. This will be very easy if your rig has dash mounted key switch and wiring.
Once you have the gearcase off, you will probably see that the plastic water tube guides that have slid upwards on the water tubes….