Excessive fuel consumption with a Weber progressive carburettor

Hello RAMVA!

I am getting lower than expected fuel consumption on my 1975 1303
(Super Beetle). It has an AR code 1300 engine that in the past someone
has rebuilt into a 1600 and fitted a dual progressive Weber
carburettor.

I've owned the car about a month, the previous owner had parked it in
a garage for between eighteen months and two years as it failed the
MoT with framehead rot. It has now been fixed, and the engine given
all new service parts - about the only thing I haven't touched is the
carb, mainly since I have never set up a Weber before! I've had the
car on the road being driven daily since Tuesday 7th November.

Currently, 24 litres of fuel gets me 100 miles - that works out at
around 16 Miles per US Gallon!!! I'm not expecting amazing fuel
economy, but at a cost of £0.90 ($1.71) per litre it is a little tough
on my wallet...

In comparison, my '66 1300 with a complete stock setup (30 PICT-1)
gets around 25 miles per US Gallon.

The manifold and air filter on the 1303 are from Scat, and the
manifold is the type with the heat risers. They look relatively new,
and since the car has only covered 10,000 miles since 1990 I don't
think they have a lot of mileage on them either.

Any idea what to check? After the 30 PICT-1 on my '66 1300 the Weber
looks quite scary The plugs, points, cap, condenser, leads and plugs
where all replaced two weeks ago during the recommissioning. It's also
had the timing, valves, etc done. Everything you would expect with a
good service.

The thing is, the car is running beautifully at the moment - no
hesitation or backfiring - nice and smooth just as you would expect.
The exhaust is a horrible 4-tip Monza, I would fit a stock one but a
previous owner fitted a smooth rear valance so it won't fit.

Can anybody help me with the procedures to check the choke is set
correctly?

Thanks in advance!
--
Howard Rose
www.howard81.co.uk
1966 Volkswagen 1300 Deluxe
1975 Volkswagen 1303S
1962 Austin Mini Seven

Howard Rose wrote:
> Hello RAMVA!
>
> I am getting lower than expected fuel consumption on my 1975 1303
> (Super Beetle). It has an AR code 1300 engine that in the past someone
> has rebuilt into a 1600 and fitted a dual progressive Weber
> carburettor.
>
> I've owned the car about a month, the previous owner had parked it in
> a garage for between eighteen months and two years as it failed the
> MoT with framehead rot. It has now been fixed, and the engine given
> all new service parts - about the only thing I haven't touched is the
> carb, mainly since I have never set up a Weber before! I've had the
> car on the road being driven daily since Tuesday 7th November.
>
> Currently, 24 litres of fuel gets me 100 miles - that works out at
> around 16 Miles per US Gallon!!! I'm not expecting amazing fuel
> economy, but at a cost of £0.90 ($1.71) per litre it is a little tough
> on my wallet...
>
> In comparison, my '66 1300 with a complete stock setup (30 PICT-1)
> gets around 25 miles per US Gallon.
>
> The manifold and air filter on the 1303 are from Scat, and the
> manifold is the type with the heat risers. They look relatively new,
> and since the car has only covered 10,000 miles since 1990 I don't
> think they have a lot of mileage on them either.
>
> Any idea what to check? After the 30 PICT-1 on my '66 1300 the Weber
> looks quite scary The plugs, points, cap, condenser, leads and plugs
> where all replaced two weeks ago during the recommissioning. It's also
> had the timing, valves, etc done. Everything you would expect with a
> good service.
>
> The thing is, the car is running beautifully at the moment - no
> hesitation or backfiring - nice and smooth just as you would expect.
> The exhaust is a horrible 4-tip Monza, I would fit a stock one but a
> previous owner fitted a smooth rear valance so it won't fit.
>
> Can anybody help me with the procedures to check the choke is set
> correctly?
>
> Thanks in advance!
> --
> Howard Rose
> www.howard81.co.uk
> 1966 Volkswagen 1300 Deluxe
> 1975 Volkswagen 1303S
> 1962 Austin Mini Seven



Mr. Hoover wrote something about the setup, once upon a time.. If you
look over at Aircooled.net, Mr. Connolly might have a few tip. I know he
sells the manifold with the heatriser going all the way to the top.
To get proper circulation through the heatriser you need a stock
exhaust, or a very trick header.

J.

On Thu, 16 Nov 2006 21:35:06 +0100, Berg > wrote:

>Mr. Hoover wrote something about the setup, once upon a time.. If you
>look over at Aircooled.net, Mr. Connolly might have a few tip. I know he
>sells the manifold with the heatriser going all the way to the top.
>To get proper circulation through the heatriser you need a stock
>exhaust, or a very trick header.

Thanks for the info! I have managed to find some useful information
on setting up the carb but I am still a little unsure as to which jets
would give me the best all-round economy performance. Any ideas?

The current jets are marked in this photo:
http://www.howard81.co.uk/upload/vz/weberjets.JPG

(I am unsure of the main jet on the other side as the carb needs to be
removed to access it).

The engine is a 1600 twin-port, I would guess it is a 1641 as it's a
rebuilt 1300.

I do plan to change the Monza to a stock exhaust at some point, but a
previous owner fitted a rear vanace without the tailpipe cutouts
making it rather tricky!
--
Howard Rose
www.howard81.co.uk
1966 Volkswagen 1300 Deluxe
1975 Volkswagen 1303S
1962 Austin Mini Seven