I have my pro circuit slip on installed, and my K&N direct filter installed. I have a 167.5 main (170 and 50 pilot jet going to be here soon) the needle at 1 notch from the bottom. With my 14/38 combo 1,2,3, and most of 4th is just plain nasty. Its amazing really how much power it has. But once i start to rap out 4th and then into 5th it feels like the power is really kinda flat. Like i would expect to hit the revlimiter but nothing is happening. Is this a main jet problem? I was thinking it was so i got a 170 on the way. And also will i only notice the 50 pilot jet when it is idling. If so why does everyone get these, or does it change something else except for the idle? Im kind ain the blue about what the pilot jet does and why the air screw needs to be messed with. And i have already drilled out the air screw.