clutch or electrical?

[bamaman01]

Well, I adjusted the air gap to .010 on clutch. It ran for abour 30 min. and stopped. I shut it off for
30 min and would not start I had to jump it off. This is the second new battery in ONE month. This is a 21 hp Briggs motor. Please let me know what gap it really should be and do you think its clutch or eletrical? I am at my short ropes end so please spare me from cutting the rope.

 

[RandyT]

With the engine running check the voltage at the battery with a volt meter. It should be 13.5-14.2 volts. It sounds like the mower isn't charging the battery. If the charging system isn't working, the clutch will discharge the battery until the voltage drops below a certain point and the clutch won't stay engaged, but engine will continue to run since it doesn't need power to run, other than maybe the fuel solenoid.

If the voltage is low make sure that you are getting battery voltage at the voltage regulator, if it has one, but probably does. If you have voltage there then disconnect the wires between the alternator under the flywheel and the regulator, and check the voltage across the two wires, but make sure the meter is set to AC and not DC for this test. Voltage should be 28-36 volts AC. If that voltage is correct, replace the voltage regulator.