I do not believe there would be a noticeable loss of power. A leaking head gasket or a crack in a cylinder head or bore can result in an internal leak.
When there is an internal leak, coolant will flow into the cylinder when the engine is off and during the intake stroke. So coolant level might be a little low.
What makes you think you might have a cracked cylinder?
Not sure about loss of power, but depending on where the crack leads, it would blow pressure into the coolant jacket, blowing coolant out & causing it to over heat quick. (Of course, overheating could have caused it to crack.)
could it also be metal fatigue.
I'm no mechanic, for sure. I'm not sure what all the causes of a cracked head could be. Most popular I recall tho I think is overheating, then maybe pouring cold water in it too fast with the engine shut down.
I wonder that too ...or will they be able to make one with their 3D printer?Sure is nice to be able to find major parts like that for 50+ y,o, tractors. Wonder if my heirs be able to find a head for my Kioti in 50 years? Or, more likely, in 20+ years?