Date:         Fri, 08 Jul 94 10:04:30 CDT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Joel Walker <JWALKER@ua1vm.ua.edu>
Subject:      Re: sychroning carbs

On Thu, 7 Jul 94 23:14:02 CDT tim c. brim said:
>My question lies therein.  Is there any way that I can sychronize the carbs
>myself?  I've read the Bentley and it's very explicit about how you should
>"take it to an authorized VW mechanic" to have this done.  It then gives this
>lenthy definition of how to adjust the carbs.

tim, you can do anything that the mechanics can do IF you have some equipment
and experience. mostly experience. :)  for equipment, think about what other
vehicles have multiple carbs ... like motorcycles! so check at the Honda
or Yamaha shops and see how they do it. :)  one fellow i know with honda
with three carbs built his own 'little' syncronizer: since what he wanted to
do was adjust the carbs so that they sucked equally, he got a plywood board
and  mounted three tubes/loops of water on it. he fixed up a deal so that it
would hold one end of the tubes in each carb. then he adjusted the carbs
until the levels of the water was the same in each tube. he 'improved' it
as he went along: adding a white background with black marks (so he could
better tell how much a tube was off from the next), and coloring the water
(or did he change to oil?). anyway, it's an old system that they used to
call a Manometer, i think. something like that anyway.  they also used to
use those tubes of fluid to measure air pressure on very old wind tunnels.

the tubes are set up in a S-pattern:
                                         my friend made his so that all
                  <-open to air          three tubes were very close to
            _   |                        each other.
           / \  |                         ___       |||
           | |x |x   <- fluid level      / __\      |||
           |  \_/                        |/ _\\     |||
 <-carb ---/                             ||/ \\\    |||    <- like that
                                         ||| |||    |||

>3.)  Bentley says you need a CO tester.
>Without going out and buying a couple thousand dollar Sun measurement machine
>is there a way to test the CO level?

the only way that i have ever heard of for checking the lean-rich mixture
(which is why you are checking the CO level) WITHOUT the Sun machine, is to
use a pyrometer (exhaust temp) or just a high-temp thermometer stuck up the
tailpipe. supposedly (naturally, i have not done this ... yet), you adjust
the mixture and let the engine settle for about two minutes then check the
temp. if it goes up, you are getting leaner. if it goes down (more gas),
you are getting richer. the thing i cannot remember is how the hell do you
know when it's right.

also: there are some $120 CO testers out there. if you want the address, i
can post it for you.

hope it helps.
joel