Manual - Chapter 6 - Ignition system

4. Ignition trigger assembly; removal and refitting

  1. Remove the fuel tank. See Chapter 5 - Fuel tank components: removal and refitting. Where fitted, remove the engine spoiler or belly fairing. Disconnect the trigger assembly wires at the single connector on the frame top tubes, adjacent to the radiator filler.
  2. Remove the trigger cover screws from the front of the engine front cover and withdraw the cover and its gasket.
  3. Carefully punch or scribe a reference mark from the trigger backplate across to the engine front cover so that the backplate can be refitted in its original position. Remove the two retaining Allen screws and withdraw the backplate; release the electrical lead from the grommet set in the front cover and from any clamps or ties provided which secure it to the frame.
  4. Remove the three screws which secure the ignition rotor and timing plate to the rotor flange and withdraw them, noting the locating pin.
  5. On reassembly install the timing plate and the ignition rotor noting that they can fit only one way when aligned with the mounting screw holes and locating dowel pin. Refit the three retaining screws and tighten them securely.
  6. Refit the backplate, align the marks made on dismantling, then refit and tighten the retaining Allen screws. If no marks are available, a basic setting which should allow the engine to run reasonably well can be made by aligning the edges of the cutout in the backplate exactly with the edges of the cutout in the housing. It is essential that the timing is checked properly as soon as possible after the ignition trigger is disturbed.
  7. Route the trigger lead up through the sealing grommet and up to the connector securing it to the frame out of harm's way.
  8. Refit the ignition trigger cover and gasket, tightening its screws to the specified torque wrench setting (where given).
  9. If there is any doubt about the ignition timing setting, take the machine to an authorised BMW dealer as soon as possible to have the timing checked.


4.2 Ignition trigger assembly is mounted on engine front cover


4.3 Scribe or punch reference mark before removing backplate so that it can be refitted in same position


4.4 Ignition rotor is secured to crankshaft flange by three screws


4.5 Timing plate notch aligns with cover pointer at TDC


4.6 Ignition timing basic setting can be achieved by aligning cutouts as shown - have timing checked properly as soon as possible