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RE: High Idle

To: <litfuse@isp01.net>
Subject: RE: High Idle
From: "Scott Hower" <HowerSL@worldnet.att.net>
Date: Tue, 14 May 2002 20:40:50 -0400
- ----- Original Message -----
From: "gc" <litfuse@isp01.net>
To: <mgs@autox.team.net>
Sent: Sunday, May 12, 2002 6:43 PM
Subject: High idle


> I finished a swapover from a ZS to twin HIF4s and I love it.  The car is a
> 1980 LE with a 1972-ish HC detoxed motor
> The dizzy appears to be from a '78 or '79.  The carbs have K&N filters and
> AAA needles.
>
> My problem:  High idle that won't drop down below 2200 when warm.
> Adjusting screws not even touching bottom.
> Haven't found any inleakage of air.  Mixture seems right, at least for
> that idle.

Not sure if this is your problem, but I had a similar situation:  73 B with
HIF4's; the throttle discs were centered and closing completely - even with
the linkages uncoupled and the idle screws backed out (removed!) I could not
get the *&%$#  idle speed under 1800 rpm.  I'd read somewhere that the
little springs holding the poppet valves closed weaken over time.  This
works just like a partially open throttle.

I removed the throttle discs, snipped the little poppet valve/spring/stem
flush and soldered them shut.  A bit of cafeful filing to smooth it all out
and I can now get her to idle as low as I want.   It's easier to just
replace them with solids throttle discs, but I forgot to plan ahead and
found myself with a few free hours of MG time.

If you decide to accept this challenge, be sure to clean the disk with some
fine steel wool.  Or you will waste 5 minutes wondering why the molten
flux/solder blobs roll aimlessly around the disk and fall gracefully onto
the garage floor (or your foot)  :-)

--Scott

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