Date:         Thu, 4 Jul 1996 22:54:27 -0700
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         ddes@anet-dfw.com (David Schwarze)
Subject:      Re: '74 carburation expertise required

At 2:27 PM 7/4/96, Ron & Nat Carscadden wrote:
>I have recently installed a rebuilt 1700 angine in our '74 Westy.  I have
>replaced the vacuum distributor with a 009 unit and have also installed an
>extractor exhaust system, with straight pipes replacing the heater boxes.

No comment on those mods.  :-)

>The story goes on and ultimately the engine would idle at a fairly steady
>850 rpm but it sounds rough at idle and on acceleration and somtimes pops
>at both idle and when the rpms are decreasing.  What I need is some
>person(s) who have some experience that they would be willing to share with
>me in guiding me through the adjustment procedure and the fine tuning with
>jets etc.  I am currently running the stock 137.5 main jet with 175 air
>correction jet in each carb.  The Bently book calls for the air correction
>jet to be 155 in the 1700 engine.

I only remember the 137.5 main being stock in '72, but I don't have the
book in front of me.  I think the '74 was listed as 127.5 mains and 145 air
correction, or something like that.  Anyway, I'm also running the 137.5
main and 175 air correction and I'm not having any of the problems that you
are, but I have a 2000cc engine.  I have found that if the engine pops when
the wheels are dragging the engine, it means one of my idle mixture
adjustment screws is turned too far in.  Back them both out and see if that
helps.  It could also be that 009 distributor.  I'd put the stock
dual-diaphragm distributor back in and see if that fixes it.  If you're
like me you'll leave it there and sell the 009 to someone with a type I
motor, because your bus will run way better.  (Why does everyone think they
have to run out and buy an 009 to get performance out of their bus???)
>
>1) What should be required in terms of jetting with the current set up I
>have?  Should I be using a larger main jet? larger air correction jet? or
>one smaller and the other larger? to accommodate the increased flow from
>the exhaust system?

I don't think you can get a larger main than 137.5.  I think you should try
a smaller one, possibly.  I'd like to try 132.5/155 like Dave Kautz uses.
I wouldn't bet on your aftermarket exhaust increasing engine breathing.
I've never seen one that wasn't a piece of junk (but then again, I've never
seen yours).

>3) Is there anyone out there who has specific knowledge with these carbs
>and setting them up for better performance?

I have lots of experience with these carbs, but most of it is just from
trying things myself because nobody else seems to know very much, with a
few notable exceptions on this list.  My bus seems to run best with the
137.5/175 jets, but I can't seem to do better than 18/19 mpg on the
highway, and I'd like to do a little better so I'm going to try the smaller
jets again one of these days in search of better mileage.  Hope this
helps...

-David

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David Schwarze                   '73 VW Safare Custom Camper       (Da Boat)
Dallas, Texas, USA               '73 Capri GT 2800                (Da Beast)
e-mail: ddes@anet-dfw.com        '87 Mustang Lx 5.0          (13.986@100.81)
http://www.anet-dfw.com/~ddes    '93 Weber WG-50                  (Da Piano)
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