[ROVERNET - UK] Re: TC CARB TUNE

[Eric Russell]

That goes back to 2001 - UK tour, Paul.
Sorry I can't remember.

Eric


--- Paul Smith <Paul.Smith at auroraenergy.com.au> wrote:

> I have Never achieved the desired mixture on
> Colourtune, due to the air
> leaks on the buttefly shafts of the HD8s.
> How much was the CO meter btw?
> 
> PVS
> 
> 
> -----Original Message-----
> From: rovernet-bounces at lyris.ccdata.com
> [mailto:rovernet-bounces at lyris.ccdata.com]
> Sent: Tuesday, 4 July 2006 10:11 am
> To: rovernet at lyris.ccdata.com
> Subject: Re: [ROVERNET - UK] Re: TC CARB TUNE
> 
> 
> Another Gunson's product which I brought back from
> the
> UK is their CO Meter.  This was particularly useful
> to
> get the Rover ready for the annual emissions test.
> Tweaking the carbs created a digital readout from
> the
> tailpipe and created a lesser burning sensation on
> the
> fingertips that the colortune.  I was disappointed
> with how much yellow appeared in the window and
> difficult /impossible it was to achieve the "Bunsen
> burner" blue they recommend.
> 
> Eric
> 
> 
> --- Geoff Kirkpatrick <britcarnut at yahoo.com> wrote:
> 
> > I can vouch for the Gunson's Colortune.  I bought
> > one on Ebay several
> > years ago and have used it to set up one of my
> > 3500S' carbs.  It was
> > running very rich and popping and backfiring
> before
> > I started.  Being able
> > to watch the spark through the clear replacement
> > plug that's part of the
> > Colortune kit is a very effective way to get the
> > carb mixtures balanced,
> > and the car ran massively better when I was done. 
> > One of these is well
> > worth seeing out.
> > 
> > Geoff
> > 
> >
>
*******************************************************
> > 
> > Message: 6
> > Date: Sun, 2 Jul 2006 20:43:44 -0400
> > From: Glen Wilson <glenwilson at cavtel.net>
> > Subject: Re: [ROVERNET - UK] TC CARB TUNE
> > To: rovernet at lyris.ccdata.com
> > Message-ID:
> > <200607022043.44921.glenwilson at cavtel.net>
> > Content-Type: text/plain;  charset="iso-8859-1"
> > 
> > (Eric, 1000 rpm sounds awfully high for a
> Rover...)
> > 
> > Larry's question mixes up about three or four
> > different issues. This is
> > the 
> > kind of stuff that drives me crazy about dual-SU
> > setups because most of
> > the 
> > procedures and advice go out the window right at
> the
> > beginning if the
> > carbs 
> > are not in tip top shape. Any leaks or worn parts
> > can mess it all up.
> > 
> > A calibration procedure must be broken down and
> > performed in a number of
> > steps 
> > in a particular order because several of the
> > adjustments are interactive
> > and 
> > affect each other. Sometimes when you are dealing
> > with two adjustments,
> > one 
> > will change the other but not vice versa.
> Therefore
> > you have to procede so
> > 
> > that when you have one setting adjusted properly,
> > you don't immediately
> > screw 
> > it up when you make the next adjustment.
> > 
> > Correct me if I'm wrong in the following because I
> > am not the guru. This
> > is a 
> > general conceptual description written as sort of
> an
> > intellectual exercise
> > to 
> > refresh my understanding.
> > 
> > 1. Basics...Get in the ballpark by setting the
> plug
> > gap, static timing,
> > point 
> > gap/dwell angle, and set the jets to the same
> number
> > of flats on both
> > carbs 
> > (how many, I don't know). When you do all of this,
> > you should be aware of 
> > whether or not you have the distributor vacuum
> > timing advance disabled or 
> > functioning, and you should make certain that the
> > little weights in the 
> > distributor for centrifugal advance are lubed and
> > able to swing freely.
> > The 
> > weights change your timing curve and ignition
> timing
> > depending on the
> > speed 
> > of your engine. Usually, when you use a timing
> > light, the vacuum advance
> > is 
> > disabled and the engine rpms are kept low enough
> > that the centrifugal
> > weights 
> > are not activated and changing the timing. The
> > engine speed at which you 
> > adjust the timing using a timing light may or may
> > NOT be the same as the 
> > basic idle speed of your engine.
> > 
> > 2. Mixture...Regardless of the amount of air
> flowing
> > through the carb, the
> > 
> > ratio of air to fuel must be within a certain
> range.
> > I would think that a 
> > tool like a Gunson Colortune sparkplug thingamajig
> > is the rational way to
> > go 
> > to get the mixture pretty close. Once you're going
> > down the road, you can 
> > check the color of the sparkplugs to see if any
> > cylinders are rich or
> > lean. 
> > I would think that the mixture (air/fuel ratio)
> > would have to be correct
> > and 
> > pretty much the same in each carb before you fine
> > tune the balance,
> > timing, 
> > or idle speed.
> > 
> > 3. Balancing...This has to do with balancing out
> the
> > volume of air flowing
> > 
> > through each of the two carbs in a given time at a
> > given engine speed. I 
> > guess the real point is to have all four cylinders
> > firing more or less
> > evenly 
> > because they are getting about the same amount of
> > fuel-air mixture. Loosen
> > 
> > the link between the carbs before attempting to
> > balance. If the carbs are 
> > good, putting the jets to the same setting should
> > result in a pretty well 
> > balanced situation. Mixture-wise, this should make
> > them pretty much the
> > same 
> > be it rich, lean or just right. You can use a carb
> > balancing tool, listen
> > to 
> > a tube for equivalent hissing sound, or whatever.
> > Regardless of what these
> > 
> > techniques tell you, the bottom line is that the
> > engine must run smoothly.
> > To 
> > my way of thinking, balancing the carbs is really
> a
> > rather fine adjustment
> > to 
> > compensate for minor manufacturing differences
> > between two carbs that are 
> > both basically within spec and with the same
> needles
> > and jets. You adjust
> > the 
> 
=== message truncated ===


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