Home › Forum › Ask A Member › Are Sierra thermostats OK? › Re: Pappy or Dan???
Help me to understand something. As you know, motors such as the 6hp under discussion here have two water flow paths through the powerhead.
The first one is through the exhaust cover, bypasses the thermostat, and exits down the back side of the cylinder head, and finally out the exhaust housing. This flow path is not thermostat controlled and is necessary to keep the exhaust system cool.
The second flow path is around the cylinders and outer edge of the cylinder head, then looks at the pellet in the thermostat. If warm enough it goes out with the first path water exit.
So, my question is if there is no bleed hole in the thermostat, isn’t there danger of an air lock around the cylinders? And if the flow is totally shut off by the lack of a bleed hole, how does the water even get to the pellet in the thermostat for sampling?
My inquiring mind needs to know.