What you are describing is normal...the intake is quite loud on these buell engines. Also keep in mind, the bottom end of these bike are a relatively large rotating mass that takes some effort to get up to RPM. It is also not recommended to snap the throttle and release real quick while sitting at idle. It is best to "roll" on the throttle and get that big ole crank rotating before you really climb into the throttle. It'll take some serious tuning and engine work to get that instantaneous throttle response commonly desired. It is the nature of the beast with these buells. It is pretty common that they fall flat when you nail it under 2000 RPMs. There are tons of posts...especially guys coming off Inline 4 bikes, that express their displeasure in the throttle response of the buell. But a Single throw, large crank V-twin just cannot rev as fast or as hard as a I-4. Just the way it is. Now, that pop/backfire could be do to the fact that you are snapping the throttle one right after the other and loading up the intake which makes it backfire through the intake. Now if this seams unreasonable, where it pops and backfires or respond even if you roll on the throttle, then that might be a cause for concern. A TPS reset might do you some good. Also, in stock form the crankcase breathers feed right back into the intake which cause quite a bit of residue to build up in the intake. Most folks do the breather reroute to keep the intake clean, some claim it helps with the low end stumble, particularly on the 12's. Anywho, best of luck! I've noticed you've posted on this before. Hope you find a satisfying answer.
