Aprilia Carburation - Weber 36DCR

[peterblenk]

Does anyone have advice/experience on fitting the Weber 36DCR carburettor to a Series II Aprilia engine? Specifically, what size main and idle jets and which emulsion tube should be used? Should the accelerator pump be used?  I've got the carburettor nicely fitted, and the linkage set up, but the tune is clearly far out. Peter Blenk

[simonandjuliet]

Any chance of a photo ? Be good to see the set up.

I will look through various books and see if I have anything

[Sebastien]

Peter,
In 2017 at the spring Lambda meeting at the Phoenix there was a nice black series II Aprilia (at the back of one picture), and I had a good discussion with the owner.
He had a register twin choke Weber fitted (more modern, the one which fitted Cortina GTs in the seventies). For that he had one of the special twin choke manifolds that Gerald Batt had reproduced. The carburettor had been set up and tuned by the following company:
http://www.aireytuning.com/#home
He was very happy about the set up, starting, running, and fuel consumption, and I could see the car was running well.
Hope this helps.

[peterblenk]

Thank you, Simon. I am in London, so probably won't make it to Phoenix soon, but I will contact Airey.
Peter

[Andrew White]

Hi Peter, I have recently put an Aprilia back on the road which last ran in 1961 and is fitted with a 36 WEBER.It doesn’t run very cleanly yet but I had to solder the float and in doing so altered the float level.I am hoping this explains the poor running! I am about to check it with an air /fuel ratio gauge to see what is happening .If it helps the 3 jets which unscrew vertically are numbered 45,115,60. That is 45 nearest the wing,60 nearest the engine.It has an accelerator pump fitted.Does anyone know what the correct fuel level is? Presumably different density of modern fuel will alter this.The engine is much happier running with a lot more ignition advance than standard. Hope some of this helps !Cheers Andrew White.

[davidwheeler]

Very many years ago I bought a Weber for an Aprilia from Cavallito and much later sold it to Gerald Batt so if anyone knows the correct setup it is likely to be a Batt.

[Kari]

Have a look at the table attached. If you need translation, let me know.  Karl

[Andrew White]

Hi Peter, Reading my post again ,I see that I put the jets in the wrong order,the main jet is nearest the wing,idle jet in the middle,accelerator pump jet nearest the engine,this is for a 36 5DR.Mine originally had  a 115 main jet which was way too lean,I have progressively drilled this out,and at 135 is now running quite well.It can look lean on initially giving it lots of throttle,but after a second or two the air fuel ratio comes down to safer levels.I may yet go to 140. The idle jet at 45 is fine,more than enough fuel.The accelerator pump for some reason doesn’t work,and so far I can’t see how to dismantle it,the car drives fine without it.Surprisingly altering the float level didn’t seem to alter things as much as expected,and I ended up setting the float horizontal with the arm which bears on the needle vertical.Hope some of this helps.