When my '84 Tecates stator was going out, it would read in spec when cold. I'd start it up and when warm enough it would shut off and not start till it cooled back down. Replacing the stator  eventually fixed the problem, but I chased it around since the ignition coil was in spec cold. Moisture played a role in the stators demise, white powder like stuff would partially cover the flywheel exterior and the bare metal on the ignition/lighting coils would show signs of rust.