Servicing Command Engines for Lawn Tractors Part Il Courtesy Kohler Company | Troubleshooting Guide 15/20/25 Amp Battery Charging Systems When problems occur in keeping the battery charged or the battery charges at too high a rate, the problem can usually be found somewhere in the charging system or with the battery. Note: Always zero ohmmeter on each scale before testing to ensure accu- ae ARSSAAM rate readings. Voltage tests should be rpm-no load. The battery must be good made with the engine running at 3600 and fully charged. Problem with 15/20/25 Amp Battery Charging System No Charge to Battery Battery Continuously Charges at High Rate Test Trace B+ lead from rectifier-regulator to key switch, or other accessible connection. Disconnect it from switch or connection. Connect an ammeter from loose end of B+ lead to positive terminal of battery. Connect DC voltmeter from loose end of B+ lead to negative terminal of battery. With engine running at 3600 RPM, read voltage on voltmeter. If voltage is 13.8 volts or more, place a minimum load of 5 amps* on battery to reduce voltage. Observe ammeter. *NOTE: Turn on lights, if 60 watts or more. Or place a 2.5 ohm, 100 watt resistor across battery terminals. Remove connector from rectifier-regulator. With engine running at 3600 RPM, measure AC voltage across stator leads using an AC voltmeter. With engine stopped, measure the resistance across stator leads using an ohmmeter. With the engine stopped, measure the resistance from each stator lead to ground using an ohmmeter. Perform same test as step 1 above. Conclusion If voltage is 13.8-14.7 and charge rate increases when load is applied, the charging system is OK and battery was fully charged. If voltage is less than 13.8 or charge rate does not increase when load is applied, test stator (Tests 2 and 3). If voltage is 28 volts or more, stator is OK. Rectifier-regulator is faulty. Replace the rectifier-regulator. If voltage is less than 28 volts, stator is probably faulty and should be replaced. Test stator further using an ohmmeter (Test 3). If resistance is 0.064/0.2 ohms, the stator is OK. If the resistance is infinity ohms, stator is open. Replace stator. If the resistance is infinity ohms (no continuity), the stator is OK (not shorted to ground). If resistance (or continuity) is measured, the stator leads are shorted to ground. Replace stator. If the voltage is 14.7 volts or less the charging system is OK. The battery is unable to hold a charge. Service battery or replace as necessary. If voltage is more than 14.7 volts, the rectifier- regulator is faulty. Replace rectifier-regulator. 3 Amp Battery Charging System with 70 Watt Lighting Stator Note: Zero ohmmeters on each scale to ensure accurate readings. Voltage tests should be made with engine run- ning at 3000 rpm-no load. Battery must be good and fully charged. See chart on next page. Electric Starting Motors Some engines in this series use iner- tia drive starting motors while most use solenoid shift starters. The inertia drive types are covered first and the solenoid shift types following. Starting Motor Precautions Note: Do not crank the engine contin- uously for more than 10 seconds at a time. If the engine does not start, allow a 60 second cool-down period between starting attempts. Failure to follow these guidelines can burn out the starter motor. Note: If the engine develops sufficient speed to disengage the starter but does not keep running (a false start), the engine rotation must be allowed to come to a complete stop before attempting to restart the engine. If the starter is engaged while the flywheel is rotating, the starter pinion and flywheel ring gear may clash, resulting in damage to the starter. Note: If the starter does not crank the engine, shut off the starter immediately. Do not make further attempts to start the engine until the condition is corrected. Note: Do not drop the starter or strike the starter frame. Doing so can damage the starter. Starter Removal and Installation Refer to the “Disassembly,” page 23, and “Reassembly,’ page 24 for starter removal and installation procedures. Inertia Drive Electric Starters This covers the operation, trouble- shooting, and repair of the inertia drive, permanent magnet electric starters. Troubleshooting Guide— Starting Difficulties Operation— Inertia Drive Starters When power is applied to the starter, the armature rotates. As the armature rotates, the drive pinion moves out on the splined drive shaft and into mesh with the flywheel ring gear. When the pinion reaches the end of the drive shaft, it rotates the fly- wheel and “cranks” the engine. When the engine starts, the flywheel rotates faster than the starter armature and drive pinion. This moves the drive pinion out of mesh with the ring gear