Splitdorf Generator Applications courtesy of Steve Blancard

This chart is based on original literature, period photographs and examining original, unrestored motorcycles. It is by no means foolproof.  Most of the original motorcycle manuals and advertising only refer to a Splitdorf generator with no reference to a specific model or rotation. 
 

ACE
 1920-1921                                                                            DU-1
 1921- up                                                                               Probably DU-5 (all CW)

CLEVELAND
 SINGLE 1922                                                                      DU-3 (CW)
 SINGLE  1923-1925                                                           DU-3 or DU-5C ? (CW)
 FOUR CYLINDER 1925 - 1928                                         DU-5C (CW)
 1928 - 1929                                                                         DU-7  (CW) may be marked “DU-7C”

EXCELSIOR
 1920? – 1921                                                                       DU-1 (CCW)
 1921 - 1924                                                                         DU-5E (CCW)
 1925 - 1928                                                                         DU-5 (CW)
 1928 - 1929                                                                         DU-7 (CW) (DU-7 possibly used on late 28 and early 29 (pre Streamliner))
 1929 - 1931                                                                         Bosch DVAR combined generator magneto (Streamliner models)

HENDERSON
 1920 – 1921                                                                         DU-1 (CW)
 1921 - 1928                                                                         DU-5 (CW)
 1928 - 1929 (last DeLuxes)                                                  DU-7 (CW) (DU-7s likely used on the last of the DeLuxes)
 1929 - 1930 (KL, KJ)                                                          DU-7 (CCW)
 1931                                                                                     Auto-lite

INDIAN
 Powerplus 1918 - 1921                                                         DU-1 (CCW)
 Prince 1925 - 4 March, 1928                                                 DU-5 (CCW)
   5 march 1928 - end of 1928 production                               DU-7 (CCW)
 (The Prince and Scout generator has a boss on the drive head, tapped 1/4-24  for mounting the belt guard on the Prince. The Scout uses the same generator, but the boss is not used.)
 Scout 1920 – 1921                                                                DU-1 (CCW)
  1921 - March 4, 1928                                                          DU-5 (CCW)
  March 5, 1928 - 26 Jan. 1931                                              DU-7 (CCW)
 Chief 1922 - 4 March 1928                                                   DU-5H (CW)
  5 March 1928 - end of 1931 production                               DU-7H (CW)
 Four Cylinder
  1927 - 4 March, 1928                                                          DU-5 (CW)
  5 March, 1928 - early 1930 production                                DU-7 (CW)
  Early 1930 production - 26 Jan. 1931                                   DU-7 (CW) Special with belt guard mounting block
  26 Jan. 1931 (late 1930 production and 1931)                      Auto-lite

MILITOR
 1920? - 1922                                                                        DU-1 (rotation?)

READING - STANDARD
 1918 - 1921??                                                                      DU-1 (CCW)
 1921 - 1924                                                                          DU-5 (CCW)
 
 

CW = Clockwise rotation when viewed from drive end

CCW = Counter-clockwise rotation when viewed from drive end