I am wondering is it possible to "burp out" air blisters from cooling system. After dissasembling and assembling elbow (one piece of broken impeler found in T pipe on inlet), I think the engine is still to hot below the head. Water temperature is 176 F after 1h ride on 2000 RPM. This seems good to me. I think water flow through the engine is OK. Question is: has everyone ever tried to vent out cooling sistem on MD7A or this is not the issue on this engine.
BR Dobra vila
Not familiar with your particular engine but if fresh water cooled you may want to carefully loosen the expansion tank cap while it is running or after it has cooled. Sometimes there may be a "bleeder" screw or cap near the top of the engine which should be opened when filling with coolant until it runs out the bleeder which should then be closed.