Originally Posted by Keldom
I can tell you that there is rattle in some cbr.. My cbr are making rattle and my friend's one don't do nothing. single cylinder 4 stroke taht make noise? Did you ever ride a motocross or some quadsport that got one cylinder? This rattle is a problem..
I also had the rattle and there is a big difference between (fairing / dash panel / loose nuts and bolts / etc rattles) and an upper engine rattle that sounds like the timing chain / valves / or rockers will fly apart at any time. To ask for help and be treated in a condescening and rude manner is not right because the condition is different and real.
Honda has dampened the motor vibrations quite well but in the max torque range (5000 - 7000 rpm) there is quite a bit of vibration while under load and things shake. In the cylinder head cover (valve cover) is a chamber that houses the pair (pulsed air induction reed) valve#4 and port plate#2. See attached pictures. These are part of the polution (smog) control system that works with the catalytic converter in the stock exhaust. The port plate#2 is held in place by the thick rubber gasket around the pair valve#4 and should not move. The side plates on mine were too short and was very loose on mine. There are corner posts where the plate should rest and when you see the corner areas on the bottom side of the port plate in the actual photo you can see wear marks where there should be none at all. My plate was jumping around all over the place inside that chamber.
I removed the plate and the metal on metal noise stopped. I don't know if that has altered the emissions or not but I do know if you install an aftermarket exhaust the catalytic converter is no longer there and the polution control system no longer functions at all. The polution control system has no effect on engine performance at all in fact if the engine were to be dyno tuned the polution control system has to be disabled to not get false exhaust reading.
Riding my bike now is like riding a totally different one (like the way it should be).