[Healeys] HD8 adjustment

[David Porter]

it is imperative to assure that the ignition timing is at the factory
recommended setting ( I think 6 degrees on a 6 cyl healey) then there should
be no problem achieving the 650-750rpm (guessing again)factory idle speed.
The HD8 carbs use an air bleed screw to set the idle speed. The other are
merely stops to keep the butterflies from sticking in the shut position. The
low idle speed corresponds with the distributors curve.
 If the idle is still too high then the mixture is likely a little too rich.
dave

frogeye at porterscustom.com

Porter Customs   2909 Arno NE
Albuquerque, NM USA 87107
505-352-1378
1954 BN2  1959 AN5
Porter Custom Bicycles

cars:
 www.britishcarforum.com/portercustoms.html
gallery:
http://picasaweb.google.com/porterscustombicycles/PorterCustomBicyclesStuff

GO HERE: http://porterbikes.com/  nice pictures-fun facts-my world

-----Original Message-----
From: healeys-bounces at autox.team.net [mailto:healeys-bounces at autox.team.net]
On Behalf Of warthodson at aol.com
Sent: Saturday, April 07, 2012 6:50 AM
To: healeys at autox.team.net
Subject: [Healeys] HD8 adjustment

When adjusting HD type carbs, I generally prefer to back off the fast idle
screw so that the throttle is fully closed (after disconnecting any
interconnecting linkage) & attempt to set the idle speed with the idle
screws.
I have no trouble doing this with HD4 & HD6 carbs. Including tricarb cars
with
both HD4's & HD6's. Yes, I know those are not the original tricarbs. My
problem & question concerns the HD8's which seem to defy being adjusted this
way. I never seem to be able to open the idle screw far enough to increase
the
idle speed to an acceptable level. In many of these cases the HD8's have
been
recently fully restored professionally & the cars are in very good
condition.
Am I correct in believing that this is a common problem?  If yes, what are
the
theories that explain why HD8's behave this way? Yes, I know there are two
(or