A friend of ours gave us a brand-new (well, almost) HD muffer for the wife's Savage.  The install went very smoothly, but now she is back-firing a lot.  If I understand it, I am going to have to re-jet the carb now.  My questions:

Do I, in fact have to re-jet?

If a re-jet is not absolutely necessary, is there an adjustment I can make on the carb to enrichen the mixture?

Finally, if re-jetting is the only option, where is the best place to buy the parts and what jet number(s) do I need?

Thanks for helping me - I may put the stock muffler back on for now because I don't want to screw anytihng up.

Well, I looked around and found some info about the "white spacer" carb mod.  I went ahead and tried this, although I did not expect it to actually solve my current issue.  The first time I tried it, I only put one small washer in and then the bike wouldn't go much over 40 MPH.  Also, it was pumping out quite a lot of black smoke.  Soooo - I took the whole thing apart a second time and added another small washer to the stack.  This time, there is still a tiny puff of black smoke when I decelerate, but the thing runs really well.  It scampers up to 60 (and  beyond) - even a little better than before, I think.

Now, the back-firing isn't totally cured, but I am not so sure it is any worse than it was with the stock muffler.  Once i actually rode the bike (my wife rode it home from the shop where we changed the muffler) I began to wonder if she wasn't just hearing the small putters and pops that I am sure were there with the stock muffler.  The difference is that this muffler is louder anyway and so she probably just didn't notice them before.  I don't know - I am really thinking I wasted my time on this carb mod.

I rode it a good 15 miles this evening and the only back-firing I heard were an occasional pop while shifting 1-2 and 2-3, plus a little puttering here and there when using engine braking.  I am not talknig about loud bangs or cracking, either - just a mild pop.  I almost like it but it may be more than the misses wants.  So - I am still considering a re-jet but I don't know if anything will completely stop this.  This bike just cleared 3000 miles so it really is just breaking in.  I have read that this engine tends to pop a bit when it is new anyway.  I wonder if this will just go away on its own.  Also, there is a small leak where the HD muffler slips over the header pipe.  I was wondering if this could be allowing air into the muffler to cause some of this popping.  I plan to tackle this leak next weekend because I want to fabricate another bracket anyway.

Does anyone know of a chrome cover that will fit over the mounting clamp when doing this modification?   Right now, I am using the stock cover but it looks a little bit dorky because there is a rather large gap around it (the HD muffler is way skinnier than the stock one.

If the Harley Muffler is baffled, not bored out and you are running the stock air cleaner you should NOT have to rejet. When you attached the HD muffler to your headerpipe, did you use a shim, like a strip of soda can, and did you REALLY tighten it down? An exhaust leak there will cause backfiring and popping. Recheck for a good fit before you take it off.
Just my 2 centavos
Ike

Be sure to adjust the pilot air adjusting screw (was under the brass plug) for highest idle speed possible.  You should be able to find a spot where the idle speed peaks, and if turned left or right it will decrease.  That is the best setting for the pilot system ... let's call it the sweet spot.  Once that is done, then use the idle speed adjusting screw to set the idle speed to about 1100 rpm (normal idle speed).
The best spot for the pilot air adjusting screw is usually 1.5-2.0 turns out.  Never go beyond 3 turns out, since doing so does not leave enough tension on the little spring holding that screw in place and it can fall out ... not a good thing when going down the road.
If you are not able to find the sweet spot, then you will need to go to the next larger pilot jet, and then retune as just described.

This process is assuming that the all of the carburetor's jets and passageways are clean and clear, the floats functioning normally, vacuum line good with no leaks, etc.  If not, then it can be impossible to jet/tune properly.

The two prime causes of backfiring are a lean pilot system and exhaust air leaks.

A little popping and crackling are normal when a more free flowing muffler is installed.  It is not harmful.  The very loud SHOTGUN TYPE BANG
is not good and can be harmful.  Rejetting is definitely required when that is happening.

Smokey02, This is no joke. How would you describe the Jake brake kind of sound ? Is this a whrling sort of sound on slow down? If so what causes it? If that is  not the sort of sound as you would describe it do you or anyone else have any idea what would cause that sound (whrling sort of sound ) on slow down on a stock 96 Savage or is that just the sound te bike makes in general? I am new to this bike and want to advoid problems id I can. Thanks again to all

verslagen1, Thanks for the graphic definition.  . As soon as I am certain of this bike I will surely be adding a non-stock muffer and some other mods. I was just happy to get the oil changed along with the air filter without braking anything. First milestone. Thanks again

Sorry 'bout highjacking the thread