I wanted to have my bike sound louder and have better performance/economy by replacing the stock exhaust system with an after market set of exhaust pipes. After pricing many exhaust pipe replacement systems I decided to just "gut" the stock pipes.
I started by drilling around the inside circumference of the exhaust pipes.Then I used hammer and chisel to remove what was still hanging on, and pulled out the "guts" with pliers.Next I smoothed the inside surface with a portable grinding wheel. Then I painted the area with high temperature paint.
The pipes are much louder now, but I can't detect any improvement in performance or economy.