Because the Y-2 cylinder is still performing lower then the Y-1 Cylinder I widened the exhaust port to Y-1 specification
The Y-2 cylinder in use is lifted 0,9mm all ports heights are the same as a Y-1 cylinder now.
But the ports from the Y-1 are also chamfered, so done this on the Y-2 cylinder to.
Left side chamfering transfers ports
Right side chamfering transfers ports
Here the slightly wider exhaust port