Working on a Coolster 125CC. When I depress the brake pedal I can verify there is power to the yellow wire going to the start button on the left handlebar. Brake light also turns on. Neutral light works verifying the atv is in neutral.

However when I depress the start button I lose power to it.

If I jump across the start solenoid it cranks over and will run.

Any help greatly appreciated.

It has a remote box on the frame but I wasn't given the remote to it. Could it be in lock mode and if so, would I be getting power to the yellow wire feeding the start button with the brake pedals depressed, and then lose such power to the yellow wire when I push the start button down?

 

Take the trigger wire on the starter and run a jumper wire directly to it. Im suspecting your solenoid or starter is bad and when you use the push button it is momentarily draining the battery. Iv seen it before more so in vehicles

 

I'm kind of having the same problem. I lost my remote and I think it is in lock mode. It won't do anything. Green light is on in neutral but the starter switch is acting dead.