unknown problems with my xb9r

Air box pop or air box backfire is normal for that bike!! Not a problem!

Low end power i would assume your using regular gas?? You want to always use premium! ALSO use synthetic oils......

Very normal to get backfiring from any harley especially a street Harley!! But if it is tooo much and you feel like its affecting performance i would either try an octane booster first? very inexpensive! If you didnt re-jet your carborator after switching to an aftermarket exhaust then you should get on that??? last get the bike dynoed, and also bring it to your local Harley Dealer if you really care about your bike......

I am having some problems with my 2003 xb9r. It has race ecm exhaust and K&N and about 5500 miles on it. The problem is i am loosing low end power and loud backfire in airbox when down shifting exhust backfires when i let off the throttle. I just put in new spark plugs and changed all the oil and it didnt help. It seems it might be running too rich but i thought the ecm would fix it on its own. I was wondering if maybe i had to get it remapped or something... any ideas?Try to check the muffler packing.,,