It's a Balancing system...the Hotter the Plug the Les Rpm's have to be pulled to burn off Said amount of Gas...Hotter Plugs give the rider the ability to Putt around on the Lower RPM's in Higher gears...Say for example doing 45 mph in 6th gear. Whilst Most Riders dont do this...some to and thats why they Run a Hotter Plug. But if you wanna Shift Normally I wouldnt go Anywhere near Redline with Hotter plugs due the the facts Stated above. While it probably wouldnt Hurt it, If you want max performance at the high end of the Gearbox id Switch back to the Spec plugs for your model bike...
Hope i could Help.
:twisted:
~Jesse