A method of manufacturing a motoring system for a gas turbine having the steps of: assembling a pinned mechanical fuse, the pinned mechanical fuse including at least one shear pin; forming an outer housing; installing a reduction gear train into the outer housing, the reduction gear train having an input and an output; operably connecting a motor to the input; operably connecting a clutch to the output using the pinned mechanical fuse, the clutch in operation engages and disengages the reduction gear train; operably connecting a starter to the clutch, the starter having an output shaft; and operably connecting an accessory gearbox to the output shaft of the starter. The clutch is operably connected to the accessory gearbox through the starter and the output shaft. The at least one shear pin in operation shears when torque on the pinned mechanical fuse is greater than or equal to a selected value.