A newbie here, looking for advice on my thumper's troublesome carb-related issues. I recently bought a 2004, all-stock, good condition Savage. Basically, here's a story and I am open to feedback. I apologize for the level of detail, but would be stoked if anyone has the time to offer suggestions. The main issue is popping/cracking when shifting 1st to 2nd, sometimes 2nd to 3rd, plus residual knocking on deceleration. I cannot decide if more tuning is the trick, or the motorcycle chop-shop did not do the job I believe I paid them to do. I should add I have scoured the posts and seen all the stuff about carb rejetting, etc. Here's my Thumper story (ps: adore my thumper, issues notwithstanding!), with hopefully answerable questions following . . .
FIRST trip to shop: jardine slash-cut slip-on + white spacer removed = gone is that darn duck-for-cover backfiring. More power! Still farts when shut off. But a new issue arose: a popping/cracking sound when shifting from 1st to 2nd and sometimes 2nd to 3rd (and apart from deceleration gurgles, she still knocks - sometimes quite loudly - in 2nd gear deceleration). SECOND trip (back) to shop: supposedly the carb was rejetted (to a 155 main, 55 pilot, and white spacer to half thickness), and slip-on given some sealant treatment where it joins the exhaust. I do not notice any difference. Still pops. Still knocks. Still farts when it's shut off. It's like its own roving concert. The idle speed screw is at a leisurely (normal) idle (it never stalls, starts fine). The low-speed mixture screw is currently 3.5 turns out. Below 1.5-2 turns out and some backfiring starts to return. It seems I have to have the low-speed mixture screw about 3.25 or more turns out to diminish popping (but the popping and knocking is still prominent). But it seems to 'surge' a little (hard to describe) at 3.25 turns out and more, plus it makes the bike weather sensitive it seems (flat spot at mid-1st and sometimes mid-2nd, though minor low-speed micture tweeks seem to remove that one).
1) Anyone suggest a next step? I'm concerned the no-change (still popping on way up, knocking on way down, like a bad pop song) after supposed carb rejet means I got a phantom carb rejet (no change in carb, just in visa bill). If my carb is those specs above (addressing 'too lean'), should I need the 3.5 turns out (richened that much)? Should I keep turning out?! Is this popping/knocking/farting just the nature of the beast? But it seems others on the forum have (mostly?) tamed those aspects of the beast?
2) There's also a rattle in the jardine slip-on (isolated it by trial and error removal of parts, etc). I maybe have to send it back as defective, unless someone can suggest a doable fix if it is a problem familiar to them? (ps: the jardine pipe is a bit anti-social but I now know what people mean when they say louder is safer).

Any feedback makes you a hero.
thanks,
d

You're going to get a lot of grumble, crackle and pop (lol your exhaust sounds discription is "colorful"   ) down shifting with most open muf's.  The lower your idle speed is makes it worse.

Now that you've had the shop do the work, it should be easy for you to check, drop the bowl and grab a mirror.  If you have a hard time removing the screws, then they didn't do the work.

I don't think any exhaust should rattle.  And it seems they tried what I would've to solve the shift pops by sealing the muf/header joint.  I trust they retorqued the header bolts too?

Please explain what you mean by knock?

Even with a Jardine muffler, as open flowing as it is, I find it hard to believe that a #55 pilot jet would require going 3.5 turns out on the adjusting screw. (by the way, you should never go more than 3 turns out, lest the screw fall out when riding down the road)
Something is not right with this picture.
I would be interested to see if the pilot jet in the carb now is really the bright shiny new #55.  Like Slavy said, the jets should all be new, and new jets are bright and shiny.

I would expect that with a #55 pilot jet installed, the pilot adjustinc screw would find its happy place at around 1-1.5 turns out.

shotgun backfire = bad
crackle/pop = good to go

Thanks to all for the tips (including the 'screw might unscrew itself at greater than 3 turns out' tip). The shop only gave me back what I think is the main jet (has 145 on it). Is it normal to return all jets that were asked to be replaced (I had asked them to put in a 55 pilot too)? Also, apologies for my ignorance, but "bright and shiny" new jets means what colour, approximately? Best guess is nice new brass looking (?), but as opposed to what if the shop threw in old jets? Just spent the day riding, and asked my mate to tell me what she looks/sounds like from the back when decelerating: loud pops is his description (not the shotgun backfires it had when I first got it), plus nighttime meant he could see a spark/blue-flame. So I can revise my confusing 'knock' to something like: a loud decompression pop (i.e: like when you stick your finger in your puffed out cheek . . . think like a kid to get it). If more than 1.5 turns out with my supposed set-up (half white-spacer, 155 main, 55 pilot) means "something is off with this picture" (Lancer), should I be assuming something might be off with the shop folk? Apart from point-blank saying "did you do what you claim" (real comfortable), is this just a case of me having to lose my carburettor virginity and open her up? If so, can anyone here point me to a good guide for a first-time carb inspector? I'm a quick study.