Ok, so on my 2001 Monster 600, I performed an air box modification; basically just cutting a large hole in the top cover for less restrictive airflow. However, after doing that, I have now noticed that when I pull the throttle wide open it doesn't really do faster and in fact seems to slow down or sputter, but if I back off the throttle a bit it will speed up just fine (albeit slowly). It did not do anything like this prior to the air box mod. Could this be because it still has the stock slip-ons causing a bottleneck at the outlet from the increased intake flow? Any ideas?