I received much help from a post by Rich on his TaoTao 110 with no spark that I decided to share my experience to hopefully save you some of the hours I lost.

Bought a couple Coleman AT125UT's. As far as I can tell, they are a TaoTao in disguise. 2 worked well, 3rd would not start unless it was warmed up by a heater (It is 30 degrees outside here). Would crank all day long, just not fire/catch (not even a sputter). If it was warmed up, it would run and ride pretty good, but still not quite as good as the others.

Was getting compression, spark, fuel, and air, then noticed one morning there was no spark, then there was, but it didn't matter, it still wouldn't fire. Since I had a working atv, I put a voltmeter on the wires to the ignition coil. Got a starting voltage of up to 20v on the good one and 0.2v on the bad one. But that 0.2v was still good enough to give off a spark on the bad one.

Worked backwards from there. Changed out the stator/trigger assembly from the good atv and the bad atv fired right up.

I did not take the time to test the stator and trigger against specs, so I am not sure if one or both are bad.

Bottom line is that if you find yourself with a new atv this cold Christmas that will turn over but not start, don't forget to check the stator/trigger in the crankshaft housing.

-Brian