Motorcycle Repair: starting problems, bike cranks, regulator rectifier

Question
The bike is a 1996/7 Yamaha Virago VX535 in California OK. To start off the bike cranks and turns over when hooked up to a battery charger. But when warm and then turned off the engine doesn't start again. It cranks and the battery goes down quite fast. So i guess my question is that what might be causing this problem?

Answer
Joe,

-check the voltage on the battery terminals
with the bike running about 3000 rpm or higher.
It should be putting out around 14 volts.

-If charging looks okay, I would get your battery
load tested or replace it.

-If the charging voltage is low, you will
need to check the stator output (60 volts AC) and if it is okay
possibly replace the regulator/rectifier.

-Make sure all your fuses are okay and
check connectors for corrosion or loose wires.

-If you get a new battery, double check that
your bike is charging ok after you install it.

-If your battery is good, your starter may
be drawing too much current, check connections
and grounds first, then rebuild the starter.

-The only other thing is a engine problem
that makes it hard to turn over, like
a partial seizure etc.