[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] Syncronizing carbs

This is a copy of Dave Hall's suggestion that I saved. I shall be trying it
myself once I've fixed the brakes.

You can rig up a manometer to compare the vacuum with a length of clear
plastic tube - maybe about 1.5 metres (4 or 5 feet) would be enough.  Put
some kerosene (no worries if it gets into the engine) in the pipe, and let
it settle in the centre sag of the pipe to give maybe 6" each side of the
mid-point (amount isn't very critical, but put an elastic band around the
U-tube part to keep the arms close together).  Remove the air cleaner and
tape the ends to the air-cleaner support screws, symmetrically in each carb,
pointing down.  The movement of the kerosene surface in each arm shows the
amount of imbalance in the carb vacuums.  It's very easy to see if they are
balanced at speed too, but as you say, it isn't very critical due to the
balance-pipe(s).  Well-balanced carbs are really nice to drive with though.

I disagree that the mixture screws are used to adjust the idle speed.  The
VW method is to turn them in until the engine begins running unevenly, then
undo about 1/4 to 1/2 turn until it is smooth again.  Later info mentions
using a CO meter to check this.  The idle (throttle-stop) screws are used to
set the rpm and the balance (then the right-hand adjustable connecting rod
is matched to the distance between the spigots so it does not disturb the

If you have a spare air-cleaner assembly, you can solder a small spigot in
the air-cleaner over each carb and attach the manometer device, then adjust
with the engine under normal operating conditions for an even more
reassuring result.  I inherited such a device from a PO - much better than
inheriting problems!

UK VW Type 3 & 4 Club

----- Original Message -----
From: Henrik Larsson <notchback@home.se>
To: Type 3 Mailing list <type3@vwtype3.org>
Sent: Wednesday, August 29, 2001 10:45 AM
Subject: [T3] Syncronizing carbs

> I'm going to try to syncronize the carbs on the 1968 Notch. I have the
> factory workshop manual describing the procedure, but I don't own a
> "Syncro-Test" tool to measure the amount of air drawn into each carb.
> I remember that someone on the list said that it is possible to use a
> hose and listen at each carb instead. How do I do that?
> Henrik Larsson, Sweden
> 1964 and 1968 Notches
> -------------------------------------------------------------------
> Too much? Digest! mailto:type3-d-request@vwtype3.org Subj=subscribe

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]