I've done a lot of work recently on my '83 115hp evinrude that I got with a project boat purchase. I removed all the internal corrosion from the powerhead, replaced head gaskets and cylinder head gaskets. Replaced the exhaust cover gaskets, valve body and thermostat cover gaskets. As well as the valve body and thermostat cover themselves. And I of course replaced the thermostats, springs and valves. Oh and the deflector tubes in the cylinder heads.
The motor pumps water(all new impeller etc) great, and cools fantastic with the hoses from the cylinder heads to the valve body removed, the water coming out is lukewarm. When I install the hoses the left bank of cylinders stay cool to the touch but the right side over heats(too hot to touch). I take it apart and swap thermostats, same problem, left cool/right hot. Nothing looks out of place. Both springs and valves are free, all gasket material is trimmed up. The thermostat seals look fine. At this point the only way to keep the right side cool is to remove the thermostat. But I can't run with the left at the right temp and the right too cool. I was going to get a new thermostat but swapping them didn't fix it, and I tested them with heat and they both opened.
What's going on?
The motor pumps water(all new impeller etc) great, and cools fantastic with the hoses from the cylinder heads to the valve body removed, the water coming out is lukewarm. When I install the hoses the left bank of cylinders stay cool to the touch but the right side over heats(too hot to touch). I take it apart and swap thermostats, same problem, left cool/right hot. Nothing looks out of place. Both springs and valves are free, all gasket material is trimmed up. The thermostat seals look fine. At this point the only way to keep the right side cool is to remove the thermostat. But I can't run with the left at the right temp and the right too cool. I was going to get a new thermostat but swapping them didn't fix it, and I tested them with heat and they both opened.
What's going on?