Sorry if this is old hash...I just checked my (new to me) 04 carb jetting after discovering that the mixture screw was 4 turns out. Main was 180 (less than 190 stock?)...and the low speed was a stock 45.
I didn't have anything in my Sportster jet assortment larger than 180, but I did swap the pilot for a 48, which resulted in a mixture of barely 2 turns out.
Bike has the SE Heavy Breather, and SE slip-ons...any suggestions on the main at 2300' elevation? (my riding area can easily go from 1200' to 4000' in a day's ride.

Also, during a day's ride yesterday, she developed an awful noise that sounded like metal against metal...only at idle. Scared the crap out of me, couldn't pinpoint it. Finally pulled off the road and was getting ready to put my ear close to the cam chest...laid my hand on the right front peg which is mounted on a highway bar...and half the noise stopped! Turns out that both those pegs were mounted without the spring washers, so they were vibrating like crazy at idle only every once in awhile!
Whew!

 

Well the main should probably be a bit smaller than stock given your altitude, though a needle drop may suffice. I think you jumped too far in the 48, but you never mentioned what carburation problems you were having. Just adjust your air screw for max RPM at idle and see how it runs.

Also google your carburator and see if they give tuning advice.

 

A few thunks...

1. Its only an idle mix screw. Doesn't effect the rest of the throttle range (well, maybe a tiny amount but not worth considering).

2. If it aint broke, don't fix it. Nothing wrong with the idle mix screw being 4 turns out. Could be it was set there to get rid of off-idle carb farts. What was wrong with how the bike was running?

3. A 48 pilot is big. Rarely needs more than a 45, even for stage-1. Having the mix screw out 4 turns is fine, it won't effect the MPG but having too big a pilot jet could mean you are running too rich a lot of the time and wasting fuel - especially at altitude.

 

Only issues were carb farts and decel popping, also had to give it a bit of fuel for quick starts when hot.
I had stopped by the dealership to pick up a replacement petcock (original was leaking) and had asked them what jets they typically start with...they suggested 48/195 with my mods. The dealership that did the mods for the original owner sits about 1000' higher than where I am.

 

Had a look to see if the needle is shimmed at all?

 

No...not yet.

 

Just took it out for a spin...45 miles...no more popping on decel and no carb farts. 180/48, 2 turns out on the mix, slightly higher idle adjustment than previous (no tach), only slightly better hot starts.

 

After a decent cruise, how do the plugs look? That will tell you for sure if its too lean or rich..

 

Plugs look to be on the lean side if anything, and I've found a 190 main jet, may try it tomorrow.