I need a little help here. I had my bike sitting for about 6 weeks until I was finally able to get out and ride it. Well, it turns out it is now idling rough and is constantly misfiring(while at idle and riding). Now, here's what I've done so far- drained fuel and replaced with super unleaded, changed spark plugs and did an oil change. So far, still running the same. Anyone have a suggestion on what to check next? Bike was running perfectly before it sat.
btw, 03 Ultra Classic.

 

check fuel pressure. try some injector cleaner they mite have got gummed up from sitting. marvel mystery oil add to gas. if fuel pressure is not rite check in tank for leaking lines. first thing you should check fuel pressure not rite bike does strange crap

 

I would check for clogged injectors as well, and maybe replace the fuel in your tank with newer gas (plus injectors cleaner.)

 

fuel lines in the tank splitting and the fuel pressure regulator....

is it tossing codes?

do yourself a favor and replace the lines and regulator anyway, they do go bad ...ask me how I know

 

Ok, I did forget to mention that I did run about 1/2 tank of gas with injector cleaner. It was that leftover fuel I drained and replaced with the super. How do I check fuel pressure? Would a bad fuel regulator cause back firing?

 

Clean Idle Air Control. The solenoid can get sluggish. If that doesent help check throttel house shaft. I had a 03 heritage and the shaft broke on the TPS side and I had random missfire and very strange idle.

 

disconnect the fuel line and plug it back in at the spigot/tap on the tank, that has helped others... I don't know why... but it is free to try

the lines and regulator are cheaper than the tool to test the fuel pressure at the outlet where the hose hooks up.

If you open the gas fill, and power the bike up, the pump pressurizes, and if you hear fluid swooshing around in there when you do, it is a split line.

The regulator/line issue manifests itself by the bike stalling when it is low on gas when you roll up to a stop.

I chased check engine codes related to spark and injectors and in the end it was the effn lines, followed by the regulator the next week

 

Holy crap! That's a LOT of things that could be wrong!
I will try each of those you mention. I did already disconnect at the spigot though. As I said, the bike was running fine before it was stored a few weeks. It's strange how some of these problems mentioned would've just "magically" appeared. Maybe just a strange coincidence???

 

difference of opinion on fuel sloshing noise. Could be split line, but could also be something else. Just had a prob that checked out like that. I removed the filler cap, and turned ignition to on, while an ear down to the filler opening. sloshing noise like described. took stuff apart to check. fuel lines in tank all good. Pressure relief valve was doing its job, which created the noise.It will do that in the event of overpressure, so I checked other places that could cause the blockage, and it turned out to be the quick connect on the tank. Disconnected it, inspected it, reconnected it, and bike started and ran fine. Fuel sloshing noise went away because no overpressure. Other than that, I agree with Neggy. Try the quick connect first.