Learned some useful lessons about my GEBE setup today

Discussion in 'Rack Mounted Engines' started by AlphaGeek, Oct 14, 2008.

  1. AlphaGeek

    AlphaGeek Member

    Ran my usual checklist before riding home from work today -- refuel, activate front/rear lights, check brakes, etc., start engine. Warm afternoon, didn't need to use the choke -- pump gas bulb a few times, a couple of pulls and engine running.

    Noticed on first high-speed segment of the ride home that I was only hitting ~27mph. Weird, must be a headwind or something.

    Next high-speed segment, now I'm only doing 26-26.5mph. WTF? I hit 31mph through there on my ride home last week.

    Tried zipping up my riding jacket, that was good for 0.5mph. Tuck in, lower my profile, still only hitting 27.5mph. Hmmm...

    Engine struggles a bit climbing incline over Dumbarton bridge, speed drops as low as 21mph. Definitely way low on usable power.

    Stop at a parking lot a couple of miles later. Brakes not dragging... exhaust doesn't look obstructed... take off the air filter cover, filter looks fine.

    Oops. Choke is at 85% engaged. Must have knocked it when starting the motor. Not so much as to flood it out at idle, but definitely restrictive at speed. Back off choke completely, hey, whaddya know -- the warp drive is back online. Full speed ahead, Scotty.

    Lessons learned:
    * Partially engaged choke takes 4-5mph off top end; if power curve drops off abnormally at top end check choke first!
    * Zipping up jacket and tucking in elbows/knees is good for at least 0.5mph, but doing the bike-racer forward lean gets tiring quick with a real helmet on
    * Properly calibrated bike comp very, very helpful for monitoring performance and detecting issues, tach and EGT (exhaust gas temp) readouts would be nice too

    Heh. Hope this helps one or two other people avoid the same rookie mistake. :)


  2. Mountainman

    Mountainman Active Member

    choke -- yes -- it's important to know where that baby's at

    because it makes it best and faster when we