The Decision-Maker is a generator-set controller. It is used on generator sets from Kohler, including the 100EFOZ, 125EFOZ, 125EOZ and 12EFKOZD.
| Symptom | Cause | Remedy |
|---|---|---|
| Backfiring | . Fuel mixture too lean. . Improper timing. . Valve ‘Sticking’. | |
| Engine cranks but will not start. | . Defective main circuit board (5-4). . Foil burnt (5-5). . Defective choke. . In line fuse to ignition coil blown. | |
| Engine runs, AC voltage is present but green lamp does not come on. | 1 amp fuse blown (5-3). | |
| Engine runs, AC voltage is present, engine stops running after a short time. | Faulty exciter voltage regulator (6-7). | |
| Engine shuts down. | . 10 amp in-line fuse blown (5-3). . Radiated electrical noise from ignition circuit affecting logic circuitry in the controller. | |
| Engine starts, then stops when start switch is released (no red or green light). | Check the 110 Volt AC output at available outlet while the start button is being held on. If AC output is present, replace AC interlock board (6-10). If no 110 Volt AC output is present — a. Check for open or short circuit. b. Check brushes (6-5) for cracks or broken leads and make sure they are making proper contact on the slip rings. c. Check rotor (6-9) and stator (6-8) resistance. d. Check voltage regulator (6-7). If defective, replace voitage regulator. NOTE: Before installing apply thermal compound (thin coat) on base of regulator. e. Check stator (6-8) for grounded, open or shorted windings. | |
| Engine starts, then stops when start switch is released. | 10 amp fuse blown (5-3). If blows after replacement check for defective wiring, generator and generator voltage regulator. | |
| Engine wil! not crank properly. | Check for loose wiring connections. | |
| Engine will not crank. | . Defective switch circuit board (5-4). . Loose pin in electrical connector. . Open in foil pattern of Main Circuit Board. | |
| Hard Starting or Loss of Power | . Faulty Ignition. .a. Loose or grounded high tension or breaker point leads. .b. Improper breaker point gap and timing. .c. Defective breaker points. .d. Faulty spark plug or improper gap. .e. Faulty condenser or coil. .gasoline not getting to carburetor. a. Dirt or gum in fuel fine. b. Fuel pump faulty. c. Dirt in carburetor. d. Carburetor improperly adjusted. e. Choke faulty or improperly adjusted. | |
| High AC voltage. | . Defective voltage regulator (6-7); replace. NOTE: Before installing, use thermal compound (#287945) and apply thin coat on base of regulator). | |
| Low AC voltage. (Below 110V). | . Worn brushes (6-5). . Defective voltage regulator (6-7); replace. NOTE: Before installing use thermal compound (#287945) and apply thin coat on base of regulator. | |
| Low output or excessive drop in voltage, green lamp ‘ON’. | . Set overloaded. Reduce the foad. . Defective voltage regulator. Replace. | |
| No AC output, green lamp off. | Fuse in controller blown (5-3). | Refer to Kohler Service Manual for Repair. |
| No AC output, green lamp ‘on’. | Circuit protector left in OFF position. Reset to ON position. If the breaker trips after starting, reduce the load on the generator set. | |
| Occasional 'Skip' at High Speed | 1. Spark plug misfire or failure. | |
| Overheating | . Insufficient available cool air. . Dirty air intake screen, shroud or cooling fins. . Improper fuel. . Fuel mixture too lean. . Improper ignition timing. . Engine overloaded. . Tight tappet clearance. . Insufficient hot-air discharge opening. | |
| Short circuit. | Check all wiring and voltage regulator. |
Fault codes and symptom→remedy steps extracted from this controller’s service/owner documentation; verify against the official manual before servicing. Aggregated from the service documentation of generator sets built on this controller.