Poppet valve mariner 40 2 stroke

[Keith 1]

Well I'm changing my thermostat and came across this poppet valve.
I'm looking at it and I really cant understand how the hell it works
I understand it travels in and out but as far as I can see it does not open or close the waterflow in anyway or let water run through it.
Any comments to help me understand this please.
Cheers.

[Keith 1]

I guess this is a hard one to explain.

[neil.mccrirrick]

As the engine speed increases and the pressure of the water from the pump also increases, the poppet valve will open and allow some of the cooling water to go around the thermostat for a more efficient cooling system

[Keith 1]

Thanks Neil.
After looking again at the housing it makes sense. I didn't realise there was a side cavity for the water to be released into next to the thermostat. I just could not see what it was for and was bit baffled.
I'm getting on a bit. Sadly.
Thanks again .