Small Engines (Lawn Mowers, etc.): wont charge..., hp briggs, dc volts

Question
Hello,
10 yr old Yard Machine by MTD rider mower w/42" deck. 16.5 hp Briggs engine. Wasn't charging by read of the battery load tester I have. Battery was dead and heard the stator is like the alternator for small engines. So got almost new stator off near new mower and new battery. Still only reads 12.5V to 13V when running. My other Craftsman mower 18hp reads 16V when running. Should this one read the same? What else could be causing the no charge condition? Thanks.

Answer
12.5 to 13 volts DC is normal.  16 volts DC is high.  My motorcycle charges at 14.6 volts DC but that is borderline being too high.  Is you meter set on DC volts?

Are sure the battery is not charging?  The mower may be draining the battery when is sits.  

Have you dis-connected the battery cables and cleaned the battery terminals and cable ends with a wirebrush?

Have you tried dis-connecting the battery after you finished mowing to make sure the mower is not draining the battery?

Did you check the Briggs alternator chart for your alternator specifications?

http://www4.briggsandstratton.com/miscpdfs/RNT/alternator_replacement.pdf

http://www4.briggsandstratton.com/miscpdfs/RNT/alternator_id_a.pdf

http://www.willardssmallengines.com/alternator_chart.html

When checking the voltage, make sure you are meter is set correct, AC or DC, and make sure you measure the AC before the rectifier/diode.

Let me know what you find.
Eric