I bought a used 2004 Savage recently.  It should have 5 gears.  I go to shift into 5th and it doesn't seem to be there...  Is there a minimum speed (or rpm) to engage 5th gear?  I've been trying to hit 5th around 50-55mph.  What is this "neutral" thing between 4th and 5th I saw a couple comments about?  Thanks guys.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1240553196

It could be an adjustment.
The shifter might be bottoming out on a bolt.
Or the shift lever might be in the wrong position.
typically, there's a center punch mark on the shaft and the slot of the lever aligns with it, but might require being 1 tooth to the side.

Thank you, Verslagen.  I'll take a look at that.  

Update on my carb jetting with the Jardine Rumbler series muffler.  I bumped up the main jet to #150 and reduced the spacer to a single nylon #4 spacer (about 1/3 thinner than stock, .066" thick if I remember the descrition correctly at ACE).  I did not change the Pilot jet (still on the #52.5).  Max rpm on the air/fuel screw is still at about 2.25 turns out.  There is no noticeable drop in rpm at 3 turns out.  However, you can tell it's a bit richer and the backfire on deceleration is lessened at 3 turns out compared to 2.25 turns out.  She still wants to backfire pretty good.  I'm humbly starting to believe you that I'm not going to eliminate the backfire with the Jardine pipe.  FYI - It's a simple wrapped core - virtually an open straight pipe.

Any further suggestions on the carb tuning are appreciated.  Thanks.

Hey Ruttly.  I've been riding almost 50 years.  My shifter stomping days are long gone.  Plus, I don't know how to stomp up to 5th with my big toe.  lol

Engine off
Sitting on the bike, rock the bike forward and back, hold light pressure up on the shifter
Get it in neutral and start working through the gears.

If you haven't yet, it would not be a bad idea to get on the ground and eyeball your shift rod. The way I see it, a bent rod will upshift better than down shift.
But one of our gurus may come along and say I'm wrong.
Nothing wrong with laying down and pushing up on the shifter and see if something is keeping it from moving through its full travel. If it has the dimple in it, compare where the shift lever is to the picture.
I usually don't use the clutch to get from second to third and on up. Instead of gripping the throttle I lay my hand flat on top and shove it forward and shift right quick.
It's just a forward thrust and immediately back. Works great. It's easier when you're going to almost the end of your best torque. As in, running the snot out of it.

impossible for anyone to know what's right for you, your system is different in a different part of the world.

The difference between fourth and fifth is not a lot. Some of these guys, blessed with a memory I never had, know the ratios. If the jump from first to second wasn't so big it would be easy to ditch the clutch going through the gears, but I was never able to get it down in the few times I tried it. Just too harsh, even when it slipped in without a sound.
Have you eyeballed the shift rod?