This is the 11th research papers in a series of papers aiming at the optimal synthesis of planar mechanisms. The mechanism in hand is invented by Al-Jazari in the 12/13th century and is analyzed before by the author for a specific time ration, stroke and transmission angle. In the present work the mechanism is optimally synthesized for maximum time ratio and desired normalized stroke. Five functional constraints are defined to control the performance of the mechanism. The MATLAB optimization toolbox is used and four dimensions of the mechanism are assigned in a normalized form. Normalized stroke range from 1 to 5.45 is covered and the study shows that it is possible with Al-Jazari mechanism configuration to go to a time ratio as large as 6.3. The optimized synthesis of the mechanism can keep the transmission angle of the mechanism during complete crank rotation within a range from 45 to 116.7 degrees for the range covered for the desired normalized stroke.