Engine model number? The charging system is not keeping up with the voltage demand from the electric clutch. Battery can be weak or too small, or the stator/alternator and voltage regulator or diodes are not letting the charging system get the DC volts to the battery for charging. Do you have a voltmeter to check battery voltage before starting and with engine running ?
Voltage can not drop below 12 volts, or the electric blade clutch will drop out. Checking battery voltage before start, should be 12.5 volts or above, and with engine running at speed, the voltage should increase at least one volt, to above 13.5 if the stator/alternator is working.
minimum of 12 volts Dc!
Payment failure. Do you need call? Did you ever give me the engine model number?
Do you have good battery? How old and has it been load tested? Seems like charging system may be dropping out, and this can be voltage regulator, but with out mode number of the engine, don't know what you have for a voltage regulator.
So not a battery problem, so it has to be the charging side.