Obviously I misread the original posts as i thought you had a Mark IV like me instead of the Mark 5XL. Sorry about that. The electrical requirements should be on the machine somewhere. Either a plate like mine or on the motor itself. From that you should get either the amps directly or the power which can be converted to amps.
If the motor has a hp rating on it the power draw is hp * 0.746 = Kw (not watts). So a 1/4 hp motor is 0.25*0.746=0.1867 kw (not watts). At 120 volt supply the amps for 1/4 hp motor is 0.1897 kw*1000 = 189.7 watts/120 volts = 1.58 amps.