Weber carb on S2 Aprilia

[Raahauge]

Good evening, please can you help.
We have a Weber TIPO 36 DR5 on our Aprilia and are short of information.
It tends to spit back as if it's weak on a wide throttle on acceleration but the jets are all clean.
There appear to be just two adjustments, slow running mixture and another, which I would like to understand. Photo attached, (the bottom one).
The gasket above the float chamber is clearly not the correct one as it is not quite the right shape and some of the holes do not align correctly but this may not be important.
Mike

[Raahauge]

The picture has come out sideways so it is the one on the right.

[Kari]

Hello,
The screw with the letters E/I adjusts the idle mixture for warm or cold temperatures: Inverno = winter; Esterna = summer. However if spitting occurs at wide open throttle, then there might be additional air drawn somewere, or a reduced petrol flow.
A possibility is the ESA device which, if not properly adjusted, can draw additional air. Find attached a description of the ESA device. If you have the Augusta Newsletter No. 18 you'll find a very good description of the Weber carburettor, the Augusta one functions the same as the one for the Aprilia.
I don't think there is a gasket between the the top and the float chamber, this might be important.
For more info please send a PM and I will pass on what I have incl. jet sizes etc.

Regards   Karl

[GG]

Karl -
Is this ESA device possibly the same as the choke on the early B20 single barrel webers? That one has three positions, from fully closed, halfway and then fully open to do the following:

- off - normal running
- economizer (lean for economy or high altitude running)
- enrichen (starting)

Trying to cold start on economizer setting was quite difficult, before this got figured out. Sounds the same as you have noted above.

[Kari]

I am not familiar with the Aurelia carburettor, but most likely the ESA (ECONO-SUPER-ALIMENTATION) system works the same.

I might add that, when running at nearly full or full throttle, by pulling the the "choke" handle (or knob) fully out, additional air/petrol mixture is fed into the carburettor. Increases the power output noticeably.

Regards  Karl

[Raahauge]

Kari, thank you for that, most helpful.
I have the newsletter but did not remember the Weber info, probably because as I have a Solex.
I will investigate.
Regards
Mike

[Andrew White]

Good evening, please can you help.
We have a Weber TIPO 36 DR5 on our Aprilia and are short of information.
It tends to spit back as if it's weak on a wide throttle on acceleration but the jets are all clean.
There appear to be just two adjustments, slow running mixture and another, which I would like to understand. Photo attached, (the bottom one).
The gasket above the float chamber is clearly not the correct one as it is not quite the right shape and some of the holes do not align correctly but this may not be important.
Mike

[peterblenk]

The Weber 36DCR carburettor on my SII Aprilia also has this E/I device, but which way is it on E and which way on I? Perhaps when the letter I want is on the side of the ridge, or??
Peter

[Kari]

Right, the letter next to the ridge is the one in use.  I = Inverno = winter, E = Esterno = summer. See also drawing Weber 30DR 03.jpg and photo 2CBAFC7A-2925-4A17-B565-622DD6017DD9.jpeg further up this tread.

Regards Karl

[simonandjuliet]

That's how I set mine as well

[appiaman]

Hi were can one get parts for these
I have one off these on my car too but bits missing and some I don't now were they go.
Regards
Christo