Kohler Engine - Charging Issue
I'm having battery charging issues with the Kohler Command CV732-3011 (24 HP?) on my Kubota ZTR and am looking for advice.
While mowing one day, the engine suddenly died and wouldn't start. I started troubleshooting and found an intermittent spark problem. After a good while, I figured it was a coil or flywheel issue so I dug into all of that but really couldn't find anything wrong. While I had the engine shroud off to check the coils, I decided to pull the flywheel but didn't have a flywheel puller. So, I used the old hammer and screwdriver method and when the flywheel finally came off I found some magnets on the inside had come loose and stuck to the stator. There was no apparent damage to the stator or magnets and I found a good video on YouTube on how to reattach the magnets with JB Weld. It appears these magnets coming loose is a common Kohler problem. I followed the instructions closely as they have to be installed a certain way or the system won't work properly. To make a long story short, I couldn't figure out the original problem and brought it to the dealer who found a bad relay in the electrical system and replaced the suspect ignition switch. The engine ran great when I got it home.
A few days later, I was mowing mountains of leaves and the engine died again but wouldn't restart because the battery was dead. The battery is brand new and was hot when I started mowing. I charged the battery and it started again with problem. The mower has an electric clutch that constantly pulls current when engaged, so I figured something was wrong with the charging system.
The stator was putting up 16 volts AC at 3600 rpm (should be 30 - 40 AC volts) when disconnected from the rectifier and the rectifier was putting out 12.6 volts DC which was the same as the battery voltage. The wire from the battery to the rectifier/regulator also showed 12.6 volts DC to ground so there were no issues with this portion of the loop. Voltage at the battery was basically the same with the engine running at 3600 rpm or not running. So, I changed the stator and the rectifier with OEM Kohler parts and am getting almost the same results as before (16 AC volts output from the stator when disconnected, battery voltage out of the rectifier and good wire back to the battery).
I really don't know what else to do. Is it possible that I installed the magnets in the flywheel improperly and that's why I'm not getting good voltage out of the stator? Am I missing something simple? Could it be a diode problem?
Thanks in advance for any advice.