There are a lot of things you can check to determine if your generator needs servicing.
Most generators will have their overload protection circuits the main failure in the electrical system that when it fails they will activate an audible warning then shut down when overloaded or under voltage conditions. This is usually indicated by a failure of the electrical drive circuit that controls overload protection.
Overload detection will tell you something about what happened to your generator if it fails. As soon as overloaded condition is detected, the generators fail safe system activates which turns on an audible alarm indicating this condition has existed for some period of time or within seconds after noticing so-called information information overloading (overcurrent) has occurred in the load wiring, alternatorwiring, battery wiring or voltage regulator failure occurs and causes they occur together.