Electrical problem
 

I have a 2001 Artic Cat 4x4 full time ATV 400. The problem is it was running, shut if off and started it several times, and when we tried to turn it on again it had no power to the starter or the lights. All fuses and battery were checked and are fine. Removed the ignition switch to test and it has power when turned on but still will not start or work the dash lights. Pull started with key on and it started and everything worked and it shuts off with the key. When I tried to turn the key back on there is still no power. Any idea what the problem could be?

Check the battery could be bad and not have enough to start

Possibly the ignition switch.

So you have power to the switch right? Find the wire that runs to the starter solenoid to activate it. Using a test light, turn the key to start. If it doesn't light then you probably have a bad ignition switch. If the dash lights and headlights worked but just won't start, then I would suspect the solenoid or a bad safety switch. Since all that stuff isn't working and your battery is good (you load tested the battery right?), then pretty much all that is left is the switch. The switch is very easy to test if you have a test light.

Do all the lights and dash work when it's running when you pull start it? If so, then I'd suspect you have a bad battery.