I pulled the cylinder head and the exhaust cover off tonight and all the cooling passages seem to be open and clean. No crud and no blockages to be found. I really don’t know why I had the overheat. All I can figure at this point is weeds blocking the water inlet screen. 😕
There is a pretty good glaze on the cylinder walls. I’m certain someone has been into this motor before me and it appears to have a fair number of hours on it. It does appear to have been pretty well-maintained throughout its life though. There were some large chunks of carbon deposits behind the baffle plate under the exhaust cover. All things considered it looks pretty clean inside. No corrosion or holes in the baffle plate at all.
Here is what it looks like inside under the head and exhaust cover.
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