hello , i have a 2007 with about 32k miles . recently ive noticed my bike doing something a little strange. ill take off from my house and have the bike at 3k rpms and without moving the throttle the bike will "jump" if you will . ill be steady at 3k and it will jump up in rpms and go back down and keep doing this untill i speed up . any ideas? only mods are a PC3 and a 2 bros slip on and it only seems to do this at lower speeds.