I recently just cleaned out my clutch with brake cleaner, pads and all. I took a chunk out of one of the pads trying to get it out with my nail. Now when i start my bike it and accelerate up to 20kmh it has a loud ticking sound, almost like i tape a playing card to my fork and the rim is making it flap like when you were a kid. I am assuming that this is causing an imbalance somewhere in there, but honestly its just a guess and im not sure. Its been too cold and rainy and crappy outside to take a look and test and then look again, and then test, and then look again, and test, then try something new, and then... test. lol
You might have a clutch issue, or a chain issue. Just my two sense.