Plug burn with Expansion Chamber>?

Discussion in '2-Stroke Engines' started by geebt48cc, Aug 8, 2010.

  1. geebt48cc

    geebt48cc Member

    :helmet: The 48cc Skyhawk is running good with new SBP Expansion Chamber. I've done nothing but bolting it on the bike (someone said I should lengthen copper pipe on stock kit 1/2"? Stock is 2.5 length, right off manifold, first piece that's copper. Top end is stronger, Mid's/Low's are about the same as it was with stock muffler? It still isn't wanting to run with choke in the total down position (about mid-way) I did a plug chop and 1/4 of it is a strange almost darker gray, but the rest light tan.

    I guess still some air working in somewhere?

    Thanks Glen

  2. GearNut

    GearNut Active Member

    It could be that you have an intake leak. The grey color is most likely from the pre-mix that you run. Different additives can leave different colors on a plug.
    I know that my plug is charcoal grey in color, but the air/ fuel ratio is spot on.