Quad is brand new and was running fine then all of a sudden lost spark. I have tried disconneting the tether kill switch, taking the blackwhite wire out of cdi for handle kill switch, and unplugging the remote control shut off box by the battery. No dice.

 

Do the tests in the help diagnose stator sticky at the top of the Chinese engines section, that should help you narrow down the problem.

 

I have the same exact issue. The ATV is brand new. Ran fine for a few days. Shut off and now won't start. It will turn and turn and turn, but wont start.
Here is what I have done so far:
* Check remote kill switch to make sure it is unlocked.
* Check the tether kill switch to make sure it is pressed on all the way.
* Checked Gas and Oil.

Where can I get a service manual for the Kayo 70?

Thank you

 

You don't mention having checked for a spark at the plug. This is the first thing to do. If you have a spark, you probably have a carb problem, clean it out. If you don't have a spark, do those "help diagnose stator" tests.