Got the carb back into the Savage, and it runs GREAT.  All stock intake & exhaust, and I've got the pilot screw out (CCW) as far as it'll go without slowing the idle, then back in a half-turn.  I put three washers (total 1.5mm thick) in place of the jet needle spacer (2.7mm thick), and used a 150 main jet.

The engine either has more power, or it feels more powerful because it's running smoother.  Low power was good before, and is as good or maybe a bit better now.  Mid-range power wasn't good--it felt somewhat like it had water in the gas, altho the gas was good--power is smooth and strong now.  Max power was good before and is even better now.  Backfiring, popping, crackling, whatever, is about 99% gone.

Doing the removal/rejetting/replacement of the carburetor resulted in the idle slowing.  It's a new thrill when downshifting to 2nd for a turn, the engine dies but I don't realize it, I let the clutch out, and the rear tire locks up and leaves S's on the pavement as I try to get stopped upright and off to the side to figure out what's happening.

Also done on this new-to-me Savage are oil & filter change, de-squealed front brake*, flushed the brake fluid, aimed the headlight and installed brighter #2357 tail & turn bulbs, and near-future installation of Ed L.'s forward controls and fix the rear brake light switch cable connection.  Oh, yeah, it rides much better with 29/33 psi in the tires than it did with the 9 psi it had when it was offered to me for a test ride!

*The O.E.  brake pads' backing plates were dry and had a bit of rust.  I put a piece of fine sandpaper on a flat surface and very lightly sanded the friction surface to flatten & remove the glaze.  I put some high-temp moly caliper grease on the contact points on the back surface and edge surfaces of the backing plates that made contact with the caliper.  No more squeal.  If it returns, I could very lightly sandpaper the rotor to remove deposited pad material, but likely the best way would be install EBC organic/kevlar #FA106 pads.  Brake squeal is usually caused by rapid vibration of the pad's steel backing plate against the caliper caused by very rapid grabbing and slipping of the rotor & pad, not by the friction of the friction material on the rotor.  (Much of the time when a car or truck owner says his brakes are warped and vibrate, the real cause is the pad material unevenly deposited on the rotor causing grabbing/slipping/grabbing, etc.  A dial indicator on the rotor won't show warping.)

Thanks for the info.

The engine idled fine when I increased the idle speed.  I'll give your 1/8-to-1/4 turn-in a try as well as borrow a tach so I know what 1100 rpm actually sounds like, and can see the first reduction of rpm when the mixture is too rich.  (I like instrumentation combined with seat of the pants tuning.)