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Re: Stuck on Stupid WAS: I'm Crying "UNCLE' - ZS carb too rich

To: bwnbcg@sjm.infi.net, spitfires@Autox.Team.Net
Subject: Re: Stuck on Stupid WAS: I'm Crying "UNCLE' - ZS carb too rich
From: Atwell Haines <carbuff@scooter.net>
Date: Mon, 18 May 1998 18:19:03 -0400
At 06:48 PM 5/17/98 -0700, Brian Neuschwander wrote:
>> To recap: My '79 Spitfire, with 47,000 miles and the original ZS 150 CDE
>> carb, is running way too rich (as verified by black sooty spark plugs). I
>> can't get it to run properly since I replaced  the o-ring in the air guide
>> (dashpot) tube. No matter where I set the needle (from full rich to
>> "falling out" lean) it runs too rich. After a minute of idling the Cat
>> glows red. :-0
>
>Sounds like the autochoke is stuck on stupid.

Jokes on you.   Water choke is gone. :)

But I considered that the choke is the source of my extra gas.   I looked
in the carb bore, and lo and behold, gas seems to be spurting in from the
rear (choke side) of the carb, just inboard of the jet bridge.

Is this where the choke richens the mixture?   Anyone?
>
>Do this:  Pull the choke unit off and cut a blanking gasket (no fuel
>passage holes).  Reinstall.  The car might be hard to start, but once
>warmed up, tune everthing else.  If you problems are gone, you know the
>source.  The actual choke problem could be a number of things--Stuck or
>worn pin, stuck bimetalic spring, wrong adjustment.  

Sounds like a good plan.  The manual conversion on the carb now uses a
cable to pull the stock enrichment plate.
>
>I solved my choke problem first by installing a manual conversion. 
>After about a year of good performance, I replace the whole ZS mess with
>a Weber down draught.

Thanks Brian.   I'm trying to stick with original since I have 6 more years
of emissions tests here in NJ.  But I do have a line on a different carb.

Atwell Haines
Spittin' Spitfire


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