1. Welcome to Bike Talk, a forum for all bikers and motorcycle enthusiasts. If you are new to Bike Talk, be sure to register for free and join the conversation.

    There's always someone around willing to help out with questions or give a friendly wave back. All Harley and metric riders are welcome.

1200 Sport dual plug heads. Carb and ignition

Discussion in 'Motorcycle Tech Talk' started by Accook78, Jul 29, 2019.

  1. Accook78

    Accook78 New Member

    Joined:
    Jul 29, 2019
    Messages:
    1
    Likes Received:
    0
    IMG_20190721_082708.jpg 99 1200 Sport engine on a Redneck Engineering custom frame. Can't accelerate quickly or pull a load without bogging down. Pulled carb and disassembled. Carb seems to have had a dynojet installed from previous owner. Main jet is a 170 slow jet is 42. Everything seems to look fine. Kinda stumped unless the jets are to small. Looked at cvp for a tuner kit but they do not offer for Sporter Sport model with dual plug heads. Any insight would be appreciated. View attachment 10620 View attachment 10620
  2. Red Rider

    Red Rider Well-Known Member

    Joined:
    Jul 5, 2006
    Messages:
    1,867
    Likes Received:
    109
    Location:
    Churchill County, NV
    Don't know why you need a specific kit for a dual-plug Sporty Sport, as the carb is the same unless you go aftermarket. You probably need to up the main jet, probably to a 195 or more even, as that bike has those poor performing drag pipes and high flow air cleaner (Hypercharger?), so you've got massive flow with little or no reversion. But they look cool and are really loud, even if ya do get whipped by a Vespa in the quarter mile..:wtf:...sorry if I'm too frank, but you have to realize that the modifications you have on your bike have made it a slow, less efficient and less reliable machine.

    From what I see, the '99 Sportster 1200S is supposed to come stock with a 195 main, and 42 slow. Something is wrong. How long have you had this bike and did you ever see it run right? Are you sure it's the Sport model?

    Good luck and let us know how you fixed it. Could also be a vacuum leak, but start with a bigger jet (190 - 195) if you think that ain't it. They don't cost much.
  3. WVBiker

    WVBiker New Member

    Joined:
    Sunday
    Messages:
    10
    Likes Received:
    1
    Have you looked at how much compression you have?????

Share This Page