I recently installed a new rectifier on my 300 xplorer, and it seems like it is charging. I can start it up, turn on the lights, unhook battery and the lights still work. After about an hour or so riding with my lights on the battery is too weak to start it. The lights remain bright. Can anyone help me diagnose it.

 

Problem number 1, is the charging system of the 300 is not as strong as the larger machines. 150W I believe compared to 200 of the bigger ones.

On my 300, I had a faulty temperature sensor causing the fan to come on more than it should. It got to the point where my fan was on the whole time I was riding, which was draining the battery. It would go extra fast if I had the lights on. Less than 20 dollars later (new sensor), it was all better.

Might not be your problem, but worth checking. Also make sure that your battery is charging well... it could be on its way out too.

-Chris

 

If you have a digital votmeter, check the voltage accross the battery terminals, before running the motor, to get a baseline measurement.
Then start the motor and check the voltage while running. You might be at a slight loss at idle, so slowly rev the motor up to about 4000, and it should get up to about 14. volts. If it does, then your charging system is fine.
Then turn it off, and keep the voltmeter hooked up. Turn on the lights, and then the starter button, and watch the voltage. If it goes lower than 10 volts, charge it up, and get it load tested.
If the chargeing system is fine, and the battery is fine, then you may have a grounding wire corrorded, or the brushes are about shot on the starter motor.