Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Running voltage is not unusual at all, It will start out charging at a higher rate and drop down as the battery is charged. I never saw where over 14 volts would harm an electric clutch. Have you checked the voltage at the clutch harness to see if voltage is still at the 15 volt range? I think you concerns are for naught!
Swap the battery , charging above normal is regulator trying to charge what it sees as a low battery Also check the battery ground, you can have a bad ground, and will cause overcharging.