I have a mid 80s TRX 200, two wheel drive model. The battery isn't charging. Where do I start checking? New battery, good connections.

 

your altenator is probably worn out

 

and if its a new battery why do you need to charge it?

 

Start by looking at the connections. They need to be clean and shiney and tight.
If you have a voltmeter, you can check the output. Hook it up to the battery with the key off. note the voltage, this is the static charge. Now start it up, and see what the voltage is at idle. It may be close to the static charge, and if youre lucky it might be a shade higher. Now turn on the headlight, and rev the motor up to 4000 rpm. The voltage should get to 14.5 or so. But not excede 15.5 volts.

 

Thanks for the suggestions. I'll check the voltages, but I suspect I'll find them low. Although the battery is new, after a few starts I have to recharge it. I've already checked connections, so I am thinking the alternator/generator is the problem. Does this make sense? If so, how do I check it and then remove/replace it?

 

well maybe its a deffective battery or ya its probably the altenator because thats what charges the battery while you are driving and if i am not mistaken you can rebuild a altenator or you might be better off buying a new one

 

If the voltage is above the static charge, then the stator is working . If the voltage doesnt rise, when the motor is revving, then you can ohm the stator coils . Either too high on resistance or too low will cause a no charge condition.
Sometimes batteries are junk right out of the box, and almost all new batteries need a slow charge when new, to condition them. You can take the battery to a auto parts store, and they can do a load test, to see if the battery is good.