In <199505101241.GAA01856@triumph.cs.utah.edu>, Jay Tilton wrote:
>VRHS43A@prodigy.com (MR JOHN H TWIST) writes:
>
>>It is my
>>experience that the charts provided with the colourtune tool demand a BLUE
>>flame, when, in fact, the MG idles best with an ORANGE flame. I do not use
>>the colourtune myself, and have experiemented with it only twice -- but
>>those were my findings. GO FOR THE RED!! John Twist
>While I can't convincingly argue with the experience of a seasoned pro, and
>I'm not trying to start a "flame" war (Bwahahaha! I kill me!)
No, I kill you. BANG.
>So, with a yellow flame you're throwing too much fuel in. The only time I
>can think that you'd want a rich mixture is during acceleration. Sure, a
>rich idle mixture will probably idle smoothly, but I worry about plugs
>quickly fouling with carbon, not to mention wasted fuel. Also, those
>subject to emissions testing will most likely fail due to high HC content if
>you don't dial in a lean mixture beforehand.
>
>Probably what you really want would be a just-barely-out-of-the-yellow flame.
Yeah, I messed with this for quite some time. The Colortune
instructions imply that you ought to start with a yellow, then move
barely blue. What actually happened was that I set the idle mixture
up for minimal "pinking" (I looove British colours) by ear first. The
correct point was fairly well-defined (within about half a turn).
Later I threw on the Colortune and found blue. I backed off on the
screw (enriching the mixture) and it immediately turned yellowish, so
I most probably had hit the barely blue point by keenly honed
automotive sensibilities, or blind coincidence. I certainly won't
argue with John, who is clearly wiser in these ways, but might suggest
that maybe things are a bit different with a Weber instead of SU's
(yeah, I know, gas is gas is gas).
A. B. "Messing with my carb is the only way I'm gonna get rich" Bonds
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