Qiye Coolster won't crank
 

Our ATV has never ran well. Now it won't crank at all.

We've recharged and replaced the battery. Even with the new one, it won't crank. We've removed the plug and it still barely cranks.

What's going on with this stupid thing?

ok, you got me confused:confused:. you say it won't crank then turn around and say "it barely cranks". which is it? does it not try to turn over at all? or does it turn over and not "start" or fire up and run?
if your battery is @ >12v, then turn the key on, take a screwdriver and "jump" the two posts on the solenoid. does it crank then? if not, check the inline fuse on the circuit. you should see it on the positive side of the battery,,,,small wire OR you may have the style that has a blade fuse and is connected to the solenoid itself. report back with details.

when jumping the solenoid, take ALL safety precautions and make sure it is in neutral AND the parking brake is set so in case it starts it won't take off on you and hurt you or someone else.