Rick,
Ok, now we're getting somewhere. The throttle is designed to close all the
way (yes), true, BUT (and this is what I'm trying to get everyone to
understand) the set screws are there for the very purpose of NOT allowing
them to close all the way. They are designed to allow a very, very, very
small gap (which when set correctly has no bearing on the functioning of the
choke). They are there to dis-allow degradation of the carb body and/or the
throttle plate (butterfly) due to repeated opening and closing and premature
shaft wear.
This also applies to the fuel drains in the manifold...they also create a
"leak" of sorts. All of these '' calibrated leaks" were part of the design
and built in adjustments are provided to deal with them....
Dave
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: "frogeye" <frogeye@swcp.com>
Cc: <healeys@autox.team.net>
Sent: Friday, June 18, 2004 12:32 PM
Subject: Re: Re timing marks (carbs)
> I'm not sure that have a real understanding of the function of the
> mechanism. I used the word "choke" in quotes because the mechanism is
> actually a mixture control. Using the throttle as you describe
> precludes that usage.
> I understand that you prefer not to let the throttle close all the way.
> As I explained, and as the unit was designed, the throttle plate is,
> indeed designed to close all the way. The air is to be let in via the
> slow idle or "bypass" circuit.
> The mixture control allows for a richer mixture for cold starts. If you
> have the throttles adjusted the way you described you are not enriching
> the mixture as you are letting more air and more fuel as you pull the
> control.
> The unit is designed very well and setup properly gets you both a
> richer mixture, and a fast idle.
> as I wrote before, why would you want less?
>
> Rick
> San Diego
>
> On Jun 18, 2004, at 11:27 AM, frogeye wrote:
>
> > 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.
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