CDI Question

Discussion in '2-Stroke Engines' started by bilboby, Sep 11, 2010.

  1. bilboby

    bilboby Member

    Just finished replacing a broken BGF motor clutch spring and dismantled the complete engine at the same time for cleaning. However i've just realized that i've put back the CDI back to front ofwhich i wish for knowing if it will affect engine performance etc?


  2. HeadSmess

    HeadSmess Well-Known Member

    yep. it will run sweet backwards now though :) (they can and they will!)

    its keyed to fire at a certain point before TDC... (advance)

    put in backwards, its now keyed to fire AFTER TDC....or retarded.
    (but run backwards would be advanced :p )

    retarded means just that !
  3. Al.Fisherman

    Al.Fisherman Active Member

    From what you are asking, it seems like you are talking about the magnet in the coil. Yes they can be put on two different ways. Although you can get a 2 cycle to run backwards, these engines won't just by installing the magnet wrong. Installed wrong the engine won't run. The key controls where the magnet is when the piston is at TDC hence proper firing time. The proper position of the magnet is obtained when the cut out parts of the magnet are in the 12:00 and 6:00 position. The magnets themselves will be at 9:00 and 3:00. The key cut out on the shaft should be in about the 1:00 to 2:00 position.
    Last edited: Sep 11, 2010
  4. bilboby

    bilboby Member

    Cheers for giving a clearer explication so i'd better reverse the CDI for original position & thank's HeadSmess though i never quite understood your reply.

    MB is fun & this forum site is educational

    Good MB riding & stay safe