Motorcycle Repair: 2005 Sportster XL1200C Carb-Jetting, intermediate jet, santee exhaust

Question
After market 2.5" Snub Nose Santee exhaust.  Do you know the
original carb jet settings for my make and model?  Do you know
the recommended jets for above mentioned exhaust?  This is a
Keihn CV carb.  Currently set at 45 slow and 180 main.  Having
lots of exhaust popping on decel.

Answer
Your stock jets should be a 45 and a 150. What you need to do to jet your carb is go for a ride and not go over 3000 RPM. Ride for about 5 miles. Check your plug color. If they are white, the go bigger on the intermediate jet, if black go smaller. Then go for another ride and run over 3000 RPM. Check the plugs again and make the above changes for the main jet. The 180 is a little big for what you are running. Also, the popping can be caused from not enough back pressure on the exhaust
Good luck and happy riding
Mike