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Re: colourtuning....

To: James Carruthers <j.carruthers@rave.ac.uk>,
Subject: Re: colourtuning....
From: "T. .R. Dafforn" <td214@cam.ac.uk>
Date: Thu, 15 Nov 2001 16:55:07 +0000
Hi James,
Color (US spelling) tune does work well, Just give it a little time...
Generally because the ignition system of a spitfire is generally a bit
knackered, what you see down the plug is sort of
Blue, Blue, Blue, Yellow, Blue....
Ignore the yellow!!
Also, ignore the color tune manual, if you set it up to a totally blue flame you
invariably end up with too lean a mixture...
Wind the jets to get all yellow at idle. then wind them back until you get Blue,
Blue, Blue, Yellow, Blue.... then wind them richer 1/8 of a turn. That in my
experience is pretty perfect!
Colour of plugs is also a great guide however!
Cheers
Tim

James Carruthers wrote:

> I got my colourtune (why is it color and not colour?) and had a go at
> tuning this morning (and afternoon). I "reset" everything (mixture nuts
> to "flush" (the inside bit that is), and then 2 turns). Air intake
> balanced with the throttle screws etc etc
>
> The engine runs evenly at this point.
>
> So I put in the colourtune - and the flashes come out yellow - I change
> the mixture until white then blue. Every so often flashes of yellow -
> but mostly blue. - I repeat this with the second carb. So everything
> should be working correctly now. But it isnt - the exhaust pops every
> now and then - and the car lacks power. Its drivable - just. arrrghhh! I
> had enough fiddling about (this morning I broke two HT leads in the
> middle of tuning - I mended them and went to buy a replacement set - and
> then took all the old leads off - then realised that they're meant to go
> in order - then couldnt find haynes.... etc etc - I get the order right
> - in the process I discover the spark plug reading page - which suggests
> biscuit is perfect - I then remember a few days ago that they were
> biscuit coloured (well one anyway) - gggrrrrr) So Ive given up for today
> as its getting dark (which might actually be the best time to use a
> colourtune...)
>
> Having now bought the colourtune Im still tempted to get it tuned at the
> local specialist tuning place.... as my patience is running very thin
> now....
>
> Disgruntled, but remembering theres always tomorrow,
>
> James
>
> 1977 Pimento Red Spit with K&N's Why didnt I leave it alone!!!!
>
>

--
Tim Dafforn
University of Cambridge
Structural Medicine Unit
Cambridge Institute for Medical Research
Hills Rd, Cambridge CB2 2XY.
UK
Tel. (01223) 763230
Fax. (01223) 336827
http://smokeroom.cimr.cam.ac.uk/

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