Paul,

Did you see my post regarding vacuum leaks?  I've concluded that
there is a major vacuum leak around the point where the throttle
cable passes through the slide-throttle frame in order to actuate
the slide.  Do you have any suggestions for how to install a seal,
and what type might work best.  Here is a picture of one from
McMaster that looks like it should work, but I'm concerned about
adding more friction to the assy.  I would like to find a low
friction seal.

Mark

Yes I did and I just sent an answer but I don't think that is a problem.

However you can buy small shaft Teflon lip seals.


http://advanced-emc.com/polymer-industrial-seals.php?gclid=CMG3kp7ZwK0CFQR5hwodVwOn_g

Paul Lamar

You could get the throttle rod out of the way to be able to
machine or drill a counter bore in the assembly where you want
to seal it.  Lip or o-ring will do.  It does not have to be
tight on the shaft.  to retain it use a small flat washer and a
spring in the open rectangular area.  The spring will just hold
the seal from coming out when the throttle is closed.
If you look at a carb, the space around the throttle plates is
quite small.  A few thousandths of an inch.  On engines with a
big cam, builders would drill a 1/16 hole in the idle side by
the transfer slot so the throttle plate could be closed and
restore mixture adjustment.  Without this the throttle plate was
above the idle hole and idle mixture could not be adjusted as it
was pulling mixture from the transfer slot.
I would try a 1/16th hole in the bottom and see what happens.
The idle screw will have to be closed to get the RPM where you
want it.  Carbs can have a problem at low RPM if the throttle
shaft or the bore for the shaft are worn.  Similar problem you
describe.  The fuel entry up-stream of the plates and an
unwanted leak at the plates.  Gives erratic idle.  Without
putting bushings in the plate, seals could cover the problem.
The reason to put the throttle close to the port entry is for
throttle response which is not a big problem for AC use.  Could
you move the throttle to over the spark plugs so there is room
to put the injectors down stream of the throttle?  A few inches
of straight pipe between the 180 and the throttle with a slight
bend (22 to 45) to put the injectors in.  If the pipe is bent
down the injectors could spray straight down the pipe and be
horizontal.  You would end up with better vapourization of the
fuel with lower fuel burn and should cure most of the idle
issues.  This style p-port is not known for smooth idle, but at
2000RPM it should not be real bad.

Dale Davies

This is a slide throttle Dale.

Paul Lamar

Yes, I realize that. Just comparing to possibly offer a
solution.  EFI is like a fancy carb.  The coolant temp sensor
acts like the choke.  Other parts have purpose that can be
related to carb functions.  The slide throttle does not change
things for the engine.  It does not care how the RPM is
controlled.  Sometimes relating to existing things helps get the
grey matter around a problem.
No worries eh mate?



Dale Davies