Before adjusting the throttle screws, one of the accordian-shaped clamps
connecting the throttle shafts should be loosened to seperate the carbs from
each other. Otherwise adjusting the throttle screw one one carb will affect
the other carb's adjustment.
----- Original Message -----
From: "Lani Spahr" <lani_spahr@agilent.com>
To: <mg-tabc@egroups.com>; <mg-t@autox.team.net>
Sent: Monday, July 17, 2000 3:18 PM
Subject: SU balacing
> Hi all -
>
> Yesterday I embarqued on the final stage of my first thorough tune up of
my
> TD (I bought it last summer) which is carburetter (!) tune up and
balancing.
> I followed the procedure as outlined in Knudson's T Series Handbook. When
I
> came to centering the jet on the front carb I had a bit of trouble getting
> it centered. The problem was that it was centered with the locking nut
loose
> but when I tightened it down the piston did not seem to go all the way
down
> and "click" on the jet. After several tries I got it to center (I
think -see
> below). Now for balancing the 2 carbs:
>
> I adjusted the 2 throttle screws as described (until they just touch the
> plate and then one full turn CW), started the engine (which idled very
well
> at a slow speed) and listened with my tubing/stethoscope to the air
intakes
> at each carb. The front one (the one that I was having problems centering)
> was sucking MUCH more air than the rear, so to balance them I had to
adjust
> the rear one CW several full turns. Even backing off the front screw (to
the
> point where it isn't touching the plate at all) to get a balance results
in
> a very fast (2500 rpm) idle speed. If I proceeded to adjust the mixture
from
> this point I doubt that I could get the revs down to an acceptable speed.
>
> Now to the questions:
>
> 1. Do I still have an uncentered front jet, i.e. does an uncentered jet
> result in a greater air intake that I observe?
>
> 2. If not #1 above, do I have something wrong with the throttle plate? Is
it
> adjustable somehow other than with the external adjusting screws? As noted
> above, when both screws are adjusted the same the front carb is REALLY
> sucking air.
>
> 3. Anything else?
>
>
> Cheers,
> Lani Spahr - 1951 TD #5550
>
> Bruckner Symphony Versions Discography
> http://people.ne.mediaone.net/lspahr
>
>
>
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