I wrote to the forum in late October about my engine overheatring (180 deg.) and since then have found my problem & I fugured some folks might be interested. I previously checked the impeller, through hull, and water flow, all OK. Stumped, I began to assess the thermostat, & behold I found problem/fix right next to it! It appears that at some point in time, a ball valve was placed in the return water loop. This valve could then manually regulate the amount of warm water returning to the engine. Sort of a manual thermostat. I closed the valve a bit after running my engine to its operating temp (180), and it dropped like a rock down to 130 Degrees! I then re-adjusted it to run at a proper 150 degrees. Pretty cool, huh!