Kohler 25hp twin will not charge

Flywheel magneto is the charging system. Turned out the magnets under the fly wheel are glued in and all fell out. Pull the flywheel, important to mark the order of the magnets, sand and clean each magnet and inside of flywheel then epoxy them back in (JB weld worked for me). Replace it all and done. Otherwise a new flywheel and coil set will run you about $500. It's a pain getting it all apart, and you need a wheel puller to get flywheel off , but beats the alternative!

Could be a bad alternator or battery