Need an idea on jetting 40 Dellorto?

[Frenchy Dehoux]

 I have a 1776 cc with dual Dellorto ( 40 ) and need to have an idea where to start with the idle jets ,mains and air jets. I do not know what the customer has for a cam.

  Thanks
  Frenchy

[Bruce]

What CB supplied is pretty close.
34mm vents
140 main
60 idle
9164.2 tubes
180 air correction jet

Now here's the strange part.  For 36s, 45s and 48 DRLAs, CB supplied a 50 pump nozzle.  But in the 40s, they came with a 35.  I never could figure that out.  I have the 35s in my 40 DRLAs.

Since you are a bit higher than sea level, I bet a 135 main and a 57 idle will work for you.  Make sure you use a single vacuum adv distributor for better mileage.  Get the one from aircooled.net that's had the mechanical curve modified.

[nicolas]

What CB supplied is pretty close.
34mm vents
140 main
60 idle
9164.2 tubes
180 air correction jet

Now here's the strange part.  For 36s, 45s and 48 DRLAs, CB supplied a 50 pump nozzle.  But in the 40s, they came with a 35.  I never could figure that out.  I have the 35s in my 40 DRLAs.

Since you are a bit higher than sea level, I bet a 135 main and a 57 idle will work for you.  Make sure you use a single vacuum adv distributor for better mileage.  Get the one from aircooled.net that's had the mechanical curve modified.

i used that as well, but i went with a 55 idle. still smooth, but it is Belgium, not Arizona.