Rick, We are discussing HD's. As to H, HS they have a separate cam
adjustment for the fast idle in concert with the choke application. The
issue is whether the butterfly should be allowed to "shut" using the
internal bore of the carburetor body as the "stop" or alternatively using
the provided set screws to accomplish the task.
I don't know how much clearer I can be.
Regards,
Dave
PS, IMHO SU's have no choke "circuit" as you call it. The jet bearing is
mechanically displaced to allow more fuel to flow past the metering needle.
Frogeye@SWCP.com Taos Garage Annex in Albuquerque
'62 BT7 MK II, '54 BN1, '62 Fiat 1600S
http://www.britishcarforum.com/TaosAnnex.html
----- Original Message -----
From: "Eric (Rick) Wilkins" <wilko2@cox.net>
To: "HealeyList list" <healeys@autox.team.net>
Sent: Friday, June 18, 2004 10:14 AM
Subject: Re: Re timing marks (carbs)
> The earlier type HS carbs with no idle circuit are meant to be adjusted
> that way, with the "idle screw/throttle adjustment" method.
> The SU company did improve the design for the more common type HD carbs.
> The manufacturer did not provide an "adjustment" device. What they
> provided was a throttle stop that is meant to be actuated by the use of
> the "choke"
> If you are using the throttle plate method you have effective lessened
> the effectiveness of the choke circuit.
> When the carb is adjusted properly, pulling the choke part way is
> supposed to lower the jet slightly without opening the throttle.
> Pulling the choke futher then opens the throttle a bit for "fast idle"
> So now, if you have your throttle stop holding open, when you pull the
> choke, you are opening the throttle and lowering the jet at the same
> time.
>
> Rick
> San Diego.
>
> On Jun 18, 2004, at 7:14 AM, frogeye wrote:
>
> > OK you guys...IF the throttle stops have no purpose, as the majority
> > seem to
> > believe, then WHY did the manufacturer even bother to provide an
> > "adjustment" device when a simple non-adjustable stop would have
> > sufficed?
> > Dave
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