Oh, I know.  I suppose that I got a little sarcastic, but I have a problem with people that second guess someone that has walked the path.  Sorry to be touchy.

The Savage is not a multi cylinder bike, so carb work is easy.  You do one thing, if it doesn't work then you put it back or try something else.  In 4 years that is what I have done on 2 Savages.  I don't even pretend that I haven't screwed up...that list is longer than my successes.  However, if I recommend something to a friend, I feel it is best for them and I back it up.  Otherwise, I'd just lurk.

You can get some polishes to help remove some of the bluing.  "The Bom" is what my wife used to buff out some of the bluing on her SuperTrapp (which was the Trapp that I blued before she took it )  Any polish will dull the finish a little, because it is IN the surface metal, but it can be reduced and polished.  Takes elbow grease, but it works.

Sorry, I'm just a proud Shade Tree  8)

Greg FWIW, here is my take on Sunny's (and my) 650's jetting.
I have been reading all I can on the 650 since I bought it.See if this jives w/ your tuning experience.

There are limits to a carbs ablities.

If we only want to prevent bluing then a slightly rich mixture is what we want.
Any carbureted single likes more jet as you "uncork" it, and a single is more finicky about it's mixture as you uncork the system. They need to be richer w/ less restriction and some carbs may need more tuning to adjust for an open pipe like her Jardine.

Now examine that Jason's bike ran best with no jet change and a Supertrapp, confirming that a good carb will self adjust for air density. - More air pulls more fuel.
In addition, the Supertrapp will give some backpressure, but is a significant improvement to the stock pipe. I have read some carbs run better w/ the Supertrapp vs. an open pipe, particularly singles. The Mikuni is quite tunable so it will take some trials to find what you need, if you want to improve performance.
My Pro-stock friends all know some carbs work better than others, they will test many of the same type to find one set of "good ones", as they are looking for that last 1 Hp. That is not to say they never change jets. They change everything ...ALOT!
So how do you know?
Well a dyno is good, so is a time slip or a lap time.
Jason's dyno runs do not mention a better air filter, he hints at a dealer adjustment, heck his stock filter may have been dirty causing the carb to go richer, who knows?
In addition, I suspect his new Supertrapp uncorked his awful factory restriction and his stock 650 and Mikuni w/ the stock jet just ran better due to only that. His Mikuni didn't like the bigger jet as the Supertrapp, I suspect, is shipped to make his *stock* carb happy. One report has good results with only the spacer mod.
Makes sense to me if you have seen the inside of the factory pipe. It's awful. That is why they 'hiss' as much as they 'putt-putt'.
Carb tuning is trial and error.
Your jet numbers are right for your set-up and give us good place to start.
Sunny, Greg has "uncorked both ends of his system, 1st the intake is shorter and the K& N "pod" should be less restrictive and straightens out the air better than even a replacement K&N in our stock intakes.
I suspect that would tend to lean the mixture, more than the Supertrapp.
Second, you have a Raask straight pipe so it makes sense it is now at a 152 jet and going higher.
Sounds like you are leaner w/ a 152 and fatter (rich) w/ a 160 jet by 'seat of the pants' testing.
I would be curious to see a time slip or dyno runs w/ the Raask in current tune vs. your 10 disc Supertrapp installed and the Mikuni and re-tuned.
Sunny’s Jardine is an open ended pipe so with no other mods my guess says start w/ a 150 vs. the stock 145.
This may be a little rich, but should help with backfires and bluing. Now if she is at high altitude, she may need to lean that set up.
There is more tuning help on the Mikuni web site.

Literally, "your mileage may vary".
I bet a dollar to a donut Jason's pipe is very colorful now.

Here's his dyno chart-
http://www.thumperpage.com/articles/ls650exh.html
Sorry about he tirade, I just needed to plan my own tuneup.

Buying a load of jets and trial and error was what I had to do as the carb only came with starting point jetting and I'd altered a couple of things.

Clive W  

You'r right Greg mine is a KLX, C model which means it was dual sport, the R model is a full on enduro.
Of course mine is now a streetmoto,doesn't go off road at all. gearing works out at 102mph at the red line in top,slightly high for the lake side roads I ride on. Thinking about an another couple of teeth on the rear sprocket.

Clive W  

Not many people can get their feet down on My KLX, even with it being a bit lower with the wheels.

Clive W  

Yep it's an older one alright.  You can tell because the bowl drain is shaped different.  Should already be jetted richer too.