Running changes after run in..

[Andy Pickering]

Now its all but run in Ive noticed some changes in power, ie hesitation in responding when opening throttle and slower to pickup and plug colour lighter brown.and I also changed from RScoot exhaust to PM..
Standard 200 sil no filter

Was:
30mm dellorto
125 Main
x7 (2nd from top)
Atomiser AV266
Slide 40
Pilot 55
Choke 70

Now changed to:
122 Main
x7 (2nd from top)
Atomiser AV264
Slide 40
Pilot 55
Choke 70
Also air screw out half a turn, now improved throttle response and darker brown plug again, would this be normal after run in? just seemed to be running really well and then seemed to detoriate and get boggy with more miles on the clock.still running at 4% when would be the correct mileage to drop to 3%..!
Sorry if Ive answered my own question.