Ferrari Mailing List: Fuel Smell - 308 carbed GTS

[Hans E. Hansen (FList]

It's actually quite easy.  Some seem terrified

of the project, but they shouldn't be.  A couple
of pointers:  Use zip lock baggies to prevent mixing
up parts from one carb to another.  Also, use
separate baggies for each subassembly (ie:
baggie for choke parts - including any screws,
baggie for throttle linkage, baggie for float
bowl stuff, etc.)  And the biggest and best
advice for someone who hasn't disassembled
these:  Leave one fully assembled to use
as a reference, if necessary.

All that is needed is to thoroughly clean it,
true up the surfaces, replace gaskets, and
replace certain maintenance items like the
float needle valve - all of which should be
included in the carb overhaul kit.

As for books, etc., there is an HP Manual for
Webers, but I didn't find it absolutely necessary.
Somewhere I ran across a decent blow-up
drawing, but I forget where.  Might have been
in the Ferrari parts manual.  Oh, and BTW, when
putting them back on the car, use the official
service manual for advice on balancing the carbs.
The basic idea is to go sort of from the inside
out - balance the airflow between the two barrels
of each carb separately, then between the carbs
on each bank, and lastly balance the two banks.
Then repeat the procedure, as tinkering with
one setting can alter another.  Didn't take me
more than 15 minutes or so.
You'll need an air flow gizmo (synchrometer),
which is available from Pierce Manifolds.  Oh,
and almost forgot, count the number of turns
on the various adjustment screws - like the
idle mix screws - before you tear it apart,
as that will give you the best starting point
for trying to get a reasonable mixture and
carb sync upon first start.

The absolute worst part of the whole procedure
is getting access to the nuts holding the carbs
to the manifold.  I bought every 13mm wrench
in existence and still had trouble tightening
some of them.

Hans.

On Mon, Sep 26, 2011 at 12:16 PM, Doug and Terri Anderson <dnt [at] dock.net> wrote:

Thanks Hans –

First to answer Brian’s question – ayep, just filled up a few weeks ago and it’s been sitting since.

And now to your question Hans – stinks only when driving. 

So system is pressurized. 

Low pressure, 5 or6 #’s my guess but enough for spritz out of cracks and crevices.

Thot about carb overhaul – just cuz.  Got any good reference sources for articles or books?

Thanks

DOUG

 

 

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From: Hans E. Hansen [mailto:FList [at] hanshansen.org]
Sent: Monday, September 26, 2011 12:05 PM
To: DOUG
Cc: The FerrariList
Subject: Re: [Ferrari] Fuel Smell - 308 carbed GTS

 

Doug:

Is this problem when it's running, just sitting in
the garage, or all of the above?

See if the carb bodies are wet.  For some reason,
the pot metal that the carbs are made of tend
to warp over time.  Saw it all the time in my days
of working on Rochester and Holley carbs, and
it happened on my GT4's Webers as well.  A
carb overhaul may be in order, which will need
to include truing up all the surfaces (hint:  use
a really big ass file....).  That fixed the gas smell
on my car.

Hans.

On Mon, Sep 26, 2011 at 11:57 AM, Brian