I started it on muffs, and the water seems to be circulating good. Temp gauge went to 175 and I shut it off. If I feel the exhaust manifold it is cool to the touch, the water hose coming into the engine from the outdrive is cool (hose water), the hoses under the thermostat housing are very warm, and the one going to the exhaust manifold is cool. I have a new impeller to install, do I shop for a thermostat? Seems like it isn't opening.
