Corroded water channel

[macbee]

Hi

My 1993 Mercury 90hp engine is very cold to touch and the stream from the tell-tale is cold

In spite of this the overheat warning horn came on last time out after trolling and I haven't tried it since at high revs.

There is a hole next to the poppet valve that shouldn't be there (photos attached) and I suspect that this could be preventing the thermostat from functioning.

I am considering closing this hole with plastic metal (as we call it in Scotland).

Does anyone have any views on this and does anyone know if I should perhaps leave a small opening at this location?

 

[macbee]

Re: Corroded water channel

Hello again

I am sorry for bleating on about this but can anybody please tell me if there should be a hole at all at "C" in my photo. I want to know if I can seal this corroded hole up or if I have to leave a small aperture. "A" is the route from the thermostat (see photo in my first post) and "B" is the route via the poppet valve. Should there be a further escape at "C" ?

Thanks in anticipation