Hello and welcome to the forum. Have you checked for a code using the Data Port on the Bike? The 2009 XB12R has a TPS or Throttle position reset method that will assist you in getting the Bike started properly That Method is here on the Forum for you to use.. Also it is a Necessary Function to make the bike run properly good Idling at 1'100 rpms before it will run at all sometimes. Never Twist the Throttle when trying to start the Engine. When any changes have been done to the Buells such as Exhaust mostly the TPS RESET will at times letting it Idle a bit (5 to 7 mins. after the reset will let the ECM/ECU adjust for some of the changes. The Bike will pop a lot when you Let or Decellerate the bikes engine which is normal for any Engine when the ECM/ECU has not been tuned properly with a computer/ when changes have been made. The Bike will still run fine but will pop with Exhaust Changes.
Try this first. 2008 through 2010 Buell TPS reset.
1st-Turn Start/Kill switch to on.
2nd turn on key switch to on- Do Not start the bike.!
This next Sentence is instructional.!
Twist the throttle Fully holding for ONE full second slightly firm then Let off Smoothly to slightly firm one second each time.
You will do this Only Three times NOT FOUR Total. Do Not touch start/Kill Switch.(Leave On!).
After That!
Turn off Key Switch. NOW turn right back on. Guages will sweep the Cel Light (yellow) engine Light will go off.
Now start the Engine. IF the Engine Grunts let off the Starter Button for a second then retry to start. Once restarted and Engine is Idling at 1'100 RPMs for maybe 30 seconds rev it slightly up to 2'500 Rpms. Let Off should be ready to ride Never dog the Idle when doing a TPS reset or right after the reset. Till Engine has run for a bit.
You will need to go this now and then for a good idling bike.
There is plenty of information here on the forum for learning about your new to you bike. Amsoil 20/50 works well in the Engine and the Transmission when changing the fluids. The Transmission takes only one Quart. *Jimi