The idle mixture screw on aproperly sized intermediate jet will be 1.25 to 1.75 turns out from lightly seated according to the S&S tuning instructions. My bike, a '91 Ultra, has cored stock mufflers, SE-1 cam, SE ignition and coil,the S&S E carb and air cleaner, and stock displacement and compression. It has a #68 main jet, confirmed by a dual probe A/F dyno curve, and a .28 intermediate jet.

I originally had a #72 main jet. The change to #68 didn't make a radical difference, at WOT the bike was a little crisper,but if I hadn't changed it it would have been very OK, just not optimal. If your bike's problem is jetting related, time spent on the intermediate jetting and careful idle mixture adjustment is what will get you the most improvement. You'll probably end up with a .28intermediate. The idle air affects running from idle to approx 2000 RPM's, the intermediate from 2000 to approx 4000, main jet from 4000 and up, with some overlap. At cruise, you're running on the intermediate jet.

 

Make sure you turn off you acc pump while trying to get it tuned in . The acc pump will help hide a jet problem . I can tell you that a 31 is too large for you . That is what S&S sends with thier 124 motors .

 

This is a guide on how to set up your carb. Give it a try, it is quite definitive, and it's got pictures.

http://www.bikernet.com/SandS/PageVi...sp?PageID=1198


Oh yeah forgot to say that I believe that if bike runs ok with the choke out, of which gives it more gas then your jet is too lean, wouldn't you think?
Does that stand to reason?