OK, I've just acquired another HD. This one is a 97 Sportster 1200.
I had it out over the weekend and at cruising speed (2000-2500rpm)
it kept popping/backfiring. Seems to idle just fine, and when I get on it, it wants to come out from under me and pulls hard until I let off.
It has a stage 1 kit in it (best I can tell from air cleaner & ignition module), power cones in the exhaust and originally had un-baffled factory exhaust. I just put a set of Bassani Radius pipes on. The bike did sit for a while before I got it, and I ran some fresh fuel in it.


Does this sound like a carb problem, or should I look elsewhere ?

 

what ur spark plugs look like since it been sitting for awhile and make sure they are gapped to .40 i aquired a used sporty a couple of weeks ago the plugs was not gapped bike was all over the place put in new ngk plugs and gapped then off i went cruising

 

If it only happens at a cruise , the easy thing to do is to pull out the choke ever so slightly and see if it feels better.
If it gets better , the bike is lean at that point in the throttle range.
Try cruising at a higher speed and RPM , lets say 3,000 RPM and see if you still have this problem.
At a higher speed and RPM , the needle will be higher in the carb , if it's OK then , you should shim the needle.
To shim the needle , pick up maybe 3 #4 machine washers (home depot , lowes) install 1 or 2 under the jet needle (to raise it) and retest.
Shimming the needle brings in the taper part quicker and transitions to richer at a lower point in the throttle position.
The pipes you have are VERY free flowing and may need a bit more fuel at that point.
If you take the carb apart , let us know what jet combo you have , the stock carb is very easy to tune well.
Welcome to the Sportster Forum.
Mick