LONCIN 70CC won't start
 

My brother in law left the key on and drained my boys battery. I was able to jump start it for the longest time but during my last attempt it was really cold outside. It was cranking and cranking and cranking. Never attempted start it for more that 3 seconds. I got it running but it was cold and didn't want to keep running and before it got a chance to warm up it just stopped turning over. I replaced the battery with a brand new one and the sylinoid just clicks now but nothing else happens. Any ideas?

depending on the battery, it may need to be charged before you can use it. Put it on the charger for a few hours and try again.

Bcdudely is correct. New batteries need to be charged after you add the sulfuric acid because they come up only partially charged.

If charging the battery doesn't work then take a meter and measure the battery voltage right at your battery terminals while attempting to crank the starter motor. It should remain above 11.5 volts. What do you get?

Try jumping your quad to your car. Does the starter motor turn now?

Set your parking brake and make sure your quad is in neutral. Use a screwdriver to short together the two big studs on your starter solenoid (some sparks OK). Does you starter turn now?