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.

Ya, it’s cleaner than I expected it to be. I’m sure it’s never seen saltwater. Not too many saltwater motors here in MI. We’re unsalted here in the Great Lakes 😉 .
I have never had to deal with a salty one, but I’m sure one will sneak into the mix from time to time. I’m sure I’ll get my shot at a salty dog at some point. 😎
-Ben

Hi Garry,
That’s a very good point and i will certainly be sure to check all the possible locations for blockages. In the case of this motor, however, it has never been restored or repainted. The paint is getting pretty thin on the midsection and is about 95% gone below the A/V plate on the L/U. Could be some crud in there that i missed when changing the impeller and gearcase oil though. Im checking everything while I have it apart waiting for my gaskets to arrive.

I’m really starting to think I had a weed blockage on the water intake screen during my lake run, though. So far everything is open and clean. When i get the old girl back together I’m going to do some run time in my backyard pond before I go back to the lake and keep a close eye on the engine temp. 😎 I dont get a chance to get to the lake to run nearly as often as I would like.
-Ben

Thanks everyone for all your help so far. I’ll post again when I start getting it back together. When I get the old girl on the lake again I’ll make a video. 😎
-Ben