What Benelli said. Plus, on reassembly, wrap some tape around the ends of the field magnet bobbin and screw it onto the cover loosely. Install the cover with a screw or two (locating it on the dowels) then tighten the coil screws. There's some play in those screws and the coil is a tight fit in the rotor. Take the cover off, remove the tape, and the rotor won't scrape on the coil.