Testing Charging System
You may be having an issue where your machine’s battery isn’t staying charged or holding a charge. Let's go over the checks to see if you charging system is working as intended. You will need a multi meter to read the voltage out put out by you machine for this test. Check the voltage at your battery with the machine off. You should have a voltage some where near 12V on a fully charged battery. Next turn the machine on and try and start it with with the multimeter still hooked up. This will tell you what the battery is reading under load, if it drops below 9V your battery has a weak or bad cell and needs to be replaced. Say the battery reads good and spins the machine over fine and the machine gets started, with the multimeter hooked up to the battery while it is running, you should be getting a reading of 13-14V. Now that the machine is running, with the multimeter still hooked up to the battery, rev the engine about 3/4 throttle and watch the voltage. Hold it at 3/4 throttle for about 15 seconds and record the highest voltage it goes to. If it goes down when when the RPMs go up that means the voltage regulator is bad and needs to be replaced. If the voltage goes higher then 15-16V then you need a larger voltage regulator. This would mean that the regulator was allowing more voltage through and over charging the batter. You voltage regulator is a black box that has cooling fins on it, kind of resembles an amplifier. Most commonly has 4 wires and his bolted somewhere to the frame.