I took out the Spark Arestor of my new GTR muffler and now the bike sounds real good, but man it sure has a loud backfire sound now when you blip the throttle closed. Is this because I took out the Arrestor? It also has a dead spot now off idle if you blip open the throttle quickly. For the fuel screw, I have an easy access aftermarket installed, but someone suggested it's now too lean. Do I go counter-clockwise (closing) or clockwise (opening) to richen it? How many turns/adjustments do I make and do I just keep adjusting until the backfire goes away or is that due to the lack of a Spark Arrestor.