Before you spend too much time on the "rattle", vacuum sync and fine tune the carbs. In fact, get the entire tune up check list spot on. Cam chain rattle sounds like clicking. Lower end gear rattle sounds like clacking. If each of the 4 cylinders doesn't fire with the same strength, minute changes in crank RPM can cause gear clack and is often diagnosed as clutch rattle.
In particular, if the rattle you hear changes pitch with clutch lever activation, it is not cam chain noise you are chasing.