I picked up a bike from my brother, but when you twist the throttle you get nothing, battery shows a charge, switch is on, and ???. is it possible the motor went south?

If your bike is experiencing intermittent power, it could be that the prongs are misaligned or dirty. Or, it could be as simple as the prongs not being pushed all the way into the battery itself. Any of those issues could cause your bike to lose power, especially if you're riding on a bumpy bike path.

Thoughts -
No/poor connection between power source and motor
Motor failure
Only someone with their hands on the bike can fully diagnose.

Did you charge the new battery before fitting, this is most important.
Is the battery a top up/ gel or MF type. Top up and MF need acid to work, was battery filled with acid? If you do get the bike running check the charging rate of the alternator by connecting a multi meter to the battery terminals. A 12 volt battery should show 12.5 to 13.2 volts off the bike and around 14 volts on the bike with the engine running at 5 K revs. (half throttle).

If the lights on a the throttle are showing a full battery then try disconnecting the brake switches at the controller one at a time. If the bike works after disconnecting a brake switch then that switch is faulty and should be replaced.
There is some excellent information on trouble shooting and testing components here http://www.razorama.com/razor-installation-guides.html
also wiring diagrams here http://manuals.monsterscooterparts.com/recreational/Razor/Wiring/

The charger does not work. The red you are reading is from the dead battery or almost dead battery. Get another charger.

yes! if that's the case ,the motor is the culprit.there are 4 things that make our bike run..the a good charger, batteries, the throttle, and the motor. now that you singled out your battery and charger ,you have the throttle and your motor..1st check your throttle & make sure it stops @ a1/4 twist.check all connections, then do an extencive check of your motor for moisture or water/signs of it being wet/riding in the rain..which is a big No-No../no rain No snow, No drizzle,and no puddles clean or muddy..it is not a gas bike....remember!great tip!

yes!your battery needs replacement.....throttle clicking after a full charge is a sign,...but that's after 2years or more,depending on how it's being used..your motor can go bad before then if you been riding in the rain--wet connectors in or out the motor can not get wet for any reason..a full dirt motor bike can not get full dirty with mud..mud catains water/water and electricity don't mix/////.motor/thottle/moisture.

Maybe this will help. This is a common problem that I have had with my GV250. Almost the same bike mechanically by Hyosung.

If the battery is low on charge and you are lucky enough for the bike to start. As per normal when first started it revs higher because the bike is cold, this turns the alternator fast to give you the electricity you need to keep the bikes computer working properly. Bike will warm up and revs drop down, alternater not turning as fast, not as much electricity being made. Bike will either stall or rev up and down irradically to try to produce its own electricity. This will occur when the battery charge is low and bike is at low revs, for example when you slow down for traffic or you stop.

If this is your problem. To resolve it when you are out on the road, keep the revs up, twisting your throttle gently when you are going slow or stopped. Give the bike a good long run on the open road to give the battery some charge from the alternator.

Make sure your battery is maintained. If you dont use your bike for a while it will lose charge just sitting there doing nothing. Give the battery a good deep cycle charge or take the bike for a good long open road ride.

First, get a fresh sparkplug. Next, charge the battery. Batteries usually only last two years or less. A battery that will not hold a charge will rob electricity needed for spark. On a bump start, the flywheel generates more electricity than a kick start. Give the throttle only one twist on your morning start if your bike has a power valve. The valve gives a shot of gas when the throttle is turned. Twist too much and the engine will flood. Please rate my answer. Thanks.

Couple possibilites. If it is just a matter of your battery clips coming undone, tighten the with pair of pliers then reattach. If it cuts out, then reengages when you start pedaling, either your controler is shot, or you have a ground short on your wheel hub. How long does a charge hold, and how often does it cut out?