'83 Honda vt500c Shadow start up problem.. (regulator?)

[chunjaenim]

Hello,

I just got a used '83 honda Shadow 500 with 16K miles.
I am having trouble starting the motorcycle.
I checked the wires and I got a new battery (12v).
I charged the battery and with the multi-meter I got 12.5V reading.

The motorcycle ran fine for the first couple start-ups, and now it's dead.

The battery now reads 12v.. 11.5 with lights on..
I jump started and the reading at idle is 12.2-12.3v
At 2000RPM I get 12.5V.

I think there's a problem with either the stator or the regulator.
The battery obviously is not charging..

Am I correct on assuming problem with stator or the regulator? or is there something else I am missing?
How do I check if the stator or the regulator is working correctly?
I located both of them, but having a hard time figuring out how to check.

Any help?

Thanks


EDIT: forgot to add this. Once the bike has started, I don't have any problem with it. It doesn't stall or shutoff on it's own. Unless I turn the engine off, it stays alive.

[TechTMW]

You need to test the output of the stator. Your Haynes/Clymers/Factory manual should detail how.

[chunjaenim]

You need to test the output of the stator. Your Haynes/Clymers/Factory manual should detail how.

I don't have the manual.
Do I really need the manual to learn how to check?
BTW, I ordered the manual online yesterday and it would take about a week..
Is there any other way for me to check??
I am just so eager to ride!!

[TechTMW]

I certainly understand how you are eager to ride! But you have a 23 year old motorcycle with relatively low miles - the bike is going to need work, so it's a good thing you got your manual.

I cannot give you specifics - they are in the manual. I will say that MOST LIKELY, 12.5 at 2k rpm is too low. You should probably be getting 13.5. But that's why you need the manual. The generator uses a permanent magnet ans a wire stator coil to generate electricity. It uses a solid state (probably) regulator/rectifier to change the current from AC to DC, and to keep the voltage at a usable level... You need to unplug the stator from the reg/rec while the bike is running. Using your multimeter, you need to check that the stator output is 18 - 20 volts AC for every 1k rpm. If it's not making that much power before the reg/rec, your stator is shot and you need a new one.

[9000white]

try this site---http://cbrworld.net/forums/thread/140473.aspx

[chunjaenim]

try this site---http://cbrworld.net/forums/thread/140473.aspx

Oh that's just awesome.
I don't have time to read through it right now, but it'll definitely help me alot.
I love TMW.

Thanks