Picked up a Kazuma 110 from my neighbor that hadn't been ran in a few years. It runs fine but the push button start only works when it's cold. Once it's been running for a few minutes it won't restart with the button. The button does nothing, no click, no starter nothing.

It will still start with a screwdriver across the solenoid just fine.

 

Would say the solenoid if failing when it gets heated up.

 

might check for loose wire connection in harness losing contact when hot as well

 

Buy a new solenoid. The screw driver by passes the electric start switch or button. Usually this indicates a weak solenoid.