YTM Charging System - Help???

[Yamaha200EL]

I got on my 84 YTM 200EL and it wouldn't start - battery dead! Damn first morning of deer season and it's freezing cold and it won't start.
I checked the battery later that day and it showed that it was bad. It will charge up to 11.3volts but won't hold. The battery is two months old. I checked to see if my charging system was working. I charged the battery up and put it back in the wheeler. I checked the volts at 11.3 volts. I started it and checked the volts again. Still 11.3 volts. Now - is the charging system working. I disconnect the battery and start it up and the headlights work - higher rpms the brighter.
I wore the battery down a little to get it to start charging - so i drained it down to about 10.5 volts and started it - no difference same volts. I checked the regulator/rectifier with ohm meter and it tested fine according to the book. I checked the wires coming out of the case from the magneto and both are putting out about .5volts is this good? Help!

[Fuzzy]

HUMMMM????. I dont know much about Yamahas but dosnt sound like enough volts. Usally on a car with a 12volt system they put out 13 or so volts when the engine starts. To make enough power to run what you need to and still have enough to recharge the battery.

As far as the headlights go they might be on a different coil.

Have you checked the battery to see if it was dry?. Also Have you tried taking a reading off of the battery cables with it running without the battery hooked up. Just to see if maybe the battery is what is draining the system down. Just a thought.

[250sx]

these are 12v systems so the battery should hold at least 12.2v or so. At about 1/2 throttle you should be seeing at LEAST 12.8 or more at the battery. Sounds like your battery has gone out.
When you bought it did you use deionized, distilled water or tap water? Did you put it on a 2amp trickle charge or a regular 10amp charge? Without the right water & lower rate of charge you can cook the battery.