Easy Roll-On...No Big Gulp!

Discussion in 'Whizzer Motorized Bicycles' started by Hal the Elder, Nov 21, 2012.

  1. Hal the Elder

    Hal the Elder Member

    The following has been common to all my previous 6 motorcycles in varying degrees until they warm up, but with OSCAR, it happens even after he's hot.

    If I give him a Big Gulp of throttle, whether at idle or at cruising speed, he'll hesitate for a couple of power strokes, then resume running steadily.

    But when I gradually roll-on the throttle, then there's no hesitation from idle to red line, just smooth acceleration.

    Am I over jetted? Running rich?

    I don't find it annoying at all...just thought I'd mention it.


  2. jaguar

    jaguar Well-Known Member

    that is a symptom of too lean a mixture.
    double check your float height is set correctly because if its set wrong it can cause it to be lean or rich.
    click onto "carburetor jetting tips" on my site after clicking onto my signature link
  3. Hal the Elder

    Hal the Elder Member


    A few years ago, I was doing a lot of engine mods on OSCAR:

    1. Having the Head milled and the combustion chamber scooped by Quenton. (This was to compensate for my 3000 ft elevation.)

    2. Installing Mushroom valve lifters. (Which has no effect on engine breathing.)

    3. Advancing the valve timing on the Camshaft gear.

    4. Installing a larger Main Jet in the carb, which Quenton sent to me. (I don't remember what the jet size was.)

    5. Removing the intake restrictor plate, which was mandated by the State of California to restrict horsepower to 1.95.

    6. Replacing the stock 0.9" muffler insert with a 1.0" insert to reduce back pressure by allowing 23% better exhaust gas flow.

    With these modifications, do you still think I'm running lean?

    Last edited: Nov 21, 2012