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Re: [T3] CO tester


Well, I've got a big beaming smile on my face because I think I am finally
making some progress with my carbs/tuning (of course only time will tell).
I received the filters and probe today for my new CO tester and waited for a
break in the rain/hail to nip out and give it a go- I just couldn't wait!

Now I have no way of accurately calibrating the machine because although the
nice people at Horiba were kind enough to send me 2 out of date cans of
calibrating gas FOC, it turned out to be a higher concentration than my
tester will read :-( The correct gas is ~ 50USD !!! for a little can!!!! so
needless to say I will have to cali by trial and error.

I got it as close as possible with the gas and then used a friends modern
Audi to compare readings. His read less than 1%- mine went off the scale
(6%)!
I had been having troubles starting since I fitted my slack eliminating
springs to the carb linkages 2 weeks ago and fiddled about blind too much-
it was really bad this morning- missing terribly until warmed up. I now know
that I was running really, really rich. I screwed the left carb adjuster in
about 2 turns to bring the reading down to 3-4% after the right screw at
least a turn! I had to mess about re-balancing them and fiddling about for
about an hour but my drive home was great- oodles more power and a nice
crisp exhaust note. My last fillup got me 18mpg(UK) which was the worst for
quite a while. Fingers crossed this could be the start of something good SÂ)
Its very nice to be able to see and really know what you are doing when you
haven't got the years of experience you would need otherwise!

Oh and I got my new THK ball joints yesterday for my carb linkages so I
think I'm going to be busy this weekend. They are beautiful- almost exact
replicas of a steering rod end except they weigh 6.3g each! with tiny rubber
boots and all! They have 4mm threads and zero play with sealed in grease for
life and are totally free moving. I'm only going to use them on the short
rods on the carbs as thats all that really needs to be so good and they
weren't cheap- ended up costing 5GBP each plus tax and a lot of delivery
from Japan. And you can't unclip them like the originals. Very nice though.

Mark Seaton
'73 Fasty London


----- Original Message -----
From: "Mark Seaton" <Markse@mo-sys.com>
To: "Type 3 Mailing List" <type3@vwtype3.org>
Sent: Sunday, April 06, 2003 6:28 PM
Subject: Re: [T3] CO tester


>
> ****************************************************************
> ----- Original Message -----
> From: "Dave Hall" <dave@hallvw.clara.co.uk>
>
> > You'll probably find about 3% will serve well - the tester may only be
+-
> 0.5%
> > anyway.
> > You may need a tad more.  I think that's still within the '80s pollution
> > requirements (4% ?), not that we need worry about it in the UK.
>
> Thanks Dave. I managed to find a nice 80's pro analyser for about the same
> money as a Gunson unit. I would hope that it would be fairly accurate- you
> have to calibrate it with cans of standard gas! Bit of a pain really, but
> its a nice bit of kit. I'm waiting on a new probe assembly and some
filters
> before I can try it. BTW I found out why the Gunson needs calibrating to
> 2percent in fresh air- it actually measures CO2 levels- aparently CO2 and
CO
> levels are inversely proportional in exhaust gases. Clever!
>
> > If both carbs need adjustment, either will show a change on the CO as
you
> screw
> > in the mixture screw, but when you get down to the point where the
engine
> sounds
> > to be hunting unscrew that a bit and pay attention to the other carb.  A
> bit of
> > tweaking on one or the other alternately should get it balanced for
> mixture.
> > Adjust the idle screws with the carb balancer to balance the throttle
> openings.
> >
> > If everything is working well, that should result in that responsive and
> > even-sounding induction roar which is music to the ears!
>
> Can't wait ;-)
>
> Mark
>
>
>
> -------------------------------------------------------------------
> List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org
>
>



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