[Roadsters] Help! mechanical genius needed

Tom PRATHER tomet9 at sbcglobal.net
Thu Sep 13 13:08:23 MDT 2007


 I recently embarked on a SU carb to MC carb conversion and
now what I thought would be the least of my problem is turning into a
nightmare. These carbs (Mikuni Flat slide) pull so much vaccum that I
can't overcome the pedal resistance. These carbs work somewhat like the
SU's but with one major difference in that the center pull bellcrank
actually lifts all 4 slides, in essence I am controlling the airflow. A few
fellas around have noted to me that maybe my stock linkage is ratio
challenged. I have noted that the vertical bar where the cable links to is
approx the same length as the pedal to pivot point distance around 8
inches which puts it at around 1-1 ratio. Does the lever and fulcrum
theory come into play here? One guy says that by reducing the vertical bar
to a shorter length of say 4inch  vs 8inch that I would increase my
ratio to 2-1 effort advantage. Does this make sense? Would this really
make it somewhat effortless than before? Another from the 311s site w
as

  nice enough to suggest a floor pedal (direct lever) as in pic.
I'm wondering now whether I should experiment with my existing pedal or
just go to this floor mount. Does anyone know whether this floor mount
is more advantageous than playing around with the stock pedal? What do
you experts think? I miss driving it, down for 2 months now. Help.
                     Thanks, Tom

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