The ever popular Bosch GPA 750 motor

Available from Ellis Components for around 100 inc VAT.

Note that 750 Watts is the 'nominal' output at 3300 rpm i.e. the power it can produce all day without over-heating. Peak power output is around 1100 Watts at 2000 rpm. Stall current is around 180 amps.
 
Full spec sheet, including performance graphs, from Bosch catalogue.

Printer friendly (monochrome) version. It may not be clear from the diagram, but the shaft diameter is 12mm.

 
The armature and can. Note the built-in fan. A weakness of the motor is the attachment of the front plate - it's only crimped in place. We carefully welded along the seams, after these joints failed in Long Beach.
Note also the three M6 mounting bolts. They are at a diameter of 100mm.

 
Close up of the four brushes. Note the characteristic discolouration of the leads due to the heat generated by 180 amps!