Got my bike today, 96 Kawasaki ZZR250, and it was not starting... Fixed the issued, got it started, it was a short in one of the relays... Now that I can hear the engine running, I think I can hear a very slight knocking noise while idling. I have never heard a ZZR250 rev before and I dont know much about bikes but the only other thing i had to compare it to was an 85 model GSX250 and that engine sounded smooth. I open the throtle a bit on the ZZR to increase the revs slightly and the knocking gets faster. At around 3K it stops knocking all together and sounds normal. When the revs drop, they will drop below normal idle for a breif second and the knocking becomes a bit more obvious and you can feel it through the handle bars. Does anyone have any idea what it could be?