The cam chain drives the camshaft off the crankshaft, and after years of running it stretches as the links wear. A stretched chain throws off your cam timing, rattles on start-up, and can eventually skip a tooth and cause real damage. Fitting a fresh chain restores correct timing and quiets the top end. It is worth inspecting the tensioner and guides while you are in there.
Replaces OEM #14402-422-004
Fits