Builded engine my XL1200S

Discussion in 'Sportster Models' started by Hamsley, Nov 25, 2006.

  1. Hamsley

    Hamsley New Member

    Okay so my here's my planned engine build so far for my '03 XL1200S,
    from my research and much-appreciated input from you all:

    - NRHS Iron-lined aluminum 1250 cylinder kit, as it requires no case
    boring and includes forged pistons
    - NRHS stage 2 1200R heads tapped and threaded for dual-plug use
    - RB Racing LSR 2-1 challenge exhaust pipe
    - K&N or SE high-flow air cleaner kit

    About the dual plugs I chose to keep the dual plug setup because I
    feel that it was a key design feature on the Sport model, so it's
    more for nostalgia than performance. Although I suppose I could run
    a bit more compression this way...

    So here's my questions. I can't remember the name of the company
    that made it but in one of my mechanic's parts books was an
    aftermarket ignition for the 1200S and it wasn't HD or Screamin'
    Eagle. Does anybody know of such manufacturers? Which is best?

    My planned power/torque output is 100-110 Hp and 90-100lb/ft of
    torque, but all under 6500 rpm, with as much torque usable at 2000
    rpm as possible. What would be a good cam choice? Pushrods? I forgot
    to mention that I'd like to run between a 10.5:1 and 11:1 CR.

    Which would me more efficient and effective, Mikuni Carb or modified
    and rejetted CV? If CV, what would it need?

    Finally is there anything I'm overlooking in my build?

    I'd like to thank eveyone who has and is input[ing] advice here.
    There's no telling what my bike would turn out like had I've not
    stumbled across this usergroup. So Thank you all.
  2. GreenBike

    GreenBike Member

    Watch buying stuff from that guy. Some people have had good luck
    with him and others not so much. YMMV, but you could search the XL-
    List archives for more info in this regard. Just be aware...

    Last I heard..the paper elements in the new SE a/c kits is a real POS.

    Check out the a/c kits NRHS has. I think they may be the way to go
    to avoid the junk SE paper element.

    It would also allow you to retain your stock ignition system.

    [/quote]So here's my questions. I can't remember the name of the company
    that made it but in one of my mechanic's parts books was an
    aftermarket ignition for the 1200S and it wasn't HD or Screamin'
    Eagle. Does anybody know of such manufacturers? Which is best?[/quote]

    All aftermarket ign. systems *that I am currently aware of* do away
    with the MAP sensor on the Sport. Our OEM ign. system was pretty
    much a one off deal and a I believe a test bed for other HD products.

    That said..removing a MAP sensor in favor of an ign. system that uses
    a VOES switch is like a giant leap backwards. A VOES gives you what
    two positions and a MAP gives you how many?

    YMMV, but you might be ahead to try using what you got till it is
    proven ineffective in your application.

    Put it all together and take it to a GOOD dyno tuner. They'll tell
    you right away..same for the CV carb.

    A properly tuned CV has proven to be more than acceptable up past 100
    HP. However, the carb. crux all depends on how much money you want
    to spend and if that money spent should actually improve performance.

    In other can buy a new carb. and quite possibly gain no
    performance from it.
  3. highway

    highway New Member

    NRHS has high-flow air cleaners, so be sure to talk to them about that
    when you order.

    Honestly, I'd make sure to ask them *all* of your questions before you
    build. They're going to know combinations that work best for your
    intended goals, including riding style and plans for the bike. If it's
    a 1/4 mile warrior, that's different than a tank-to-tank trip machine,
    and both are different than a back-roads hooligan bike.

    I would keep the stock ignition until I was sure it was causing
    with reliability or power production. The aftermarket systems don't
    offer any big features you don't already have (i.e. single-fire) and
    they certainly cost more than reusing what you have.

    The OEM CV is capable of building the power you want, so it's a matter
    of what the person doing the tuning likes. If that's you, then it's up
    to you to decide how much work you're willing to put into learning one
    of the carburetors versus the other. Both have their fans, and both
    are very adjustable.

    I've kicked around a set of dual-plugged XB heads for my '03, so I'm
    very interested in how this turns out.
  4. GreenBike

    GreenBike Member

    Additional information,when I was building my bike I looked into all the different ignitions out there for the Sport. None of them offered anything better than the Scream'n Eagle Ignition. The problem is finding the Scream'n Eagle. Remember they came in 2 varieties, 6200 RPM and 7500 RPM. Despite what you might read the 2 models also had different ignition curves in them. I collected a couple of each for myself before they became really scarce and have tested both. The 6200 RPM model is great on a modified engine with the bolt-in cams. The 7500 RPM model is better suited to a motor with more aggressive caming.
  5. Geba

    Geba New Member

    Would love to get one of those SE modules if you have one for a 1998 XL1200S.

    Any for sale??