Got a 125cc Taotao atv for the kids.put new battery in new chain ,fuses all good checked all wires .no probs .cant figure why it wont even try and to start.no sound or cranking .as it is electric star

Man am in the same bote

Might be a dud starter motor but unlikely as the solenoid would still be heard clicking when pressing the starter switch. This depends on what sort of starting system it is fitted with but generally the starter motor can be checked by jumping the battery live direct to the motor positive when the motor should spin.
If it doesn't it is worth checking the ground connections and leads from the battery to the engine and to the body electrics.

If all else seems ok then the problem is likely with the switching. With things intended to be used by kids there could be safety inhibitors, such as a pressure switch under the seat so it couldn't be started until the driver is seated and perhaps another fitted to the brake to prevent starting unless the brake is applied and perhaps yet another fitted to the gearchange to prevent starting unless in neutral.

I hope this helps but if you still have trouble please come back again.

Your starter is probably out, or not properly connected. Locate the starter and there should be two wires going to it, they both should be marked with + and - make sure red goes to positive and black to -
If you want to test your starter before buying a new one, take it off of the fourwheeler, and hook it up to the battery. (note: this is not recommended by the manufacturer may void warranty. If you do do it.... Hold on to that starter.)