The Digital AVR is a generator-set controller. It is used on generator sets from Honda, including the EM4000SX, EM5000SXK3 and EM6500SXK2.
| Symptom | Cause | Remedy |
|---|---|---|
| Compression is too high | Perform the cylinder compression test (page 11-5). If the cylinder compression is too high, remove carbon deposits in the combustion chamber (page 3-10). | |
| Compression is too low | Valve spring free length, Valve seat width, Valve face irregularly worn, Decompressor operation, Piston ring side clearance, Piston ring width, Piston ring end gap, Piston skirt O.D., Cylinder sleeve I.D. | Check the valve clearance (page 3-9), and then perform the cylinder compression test (page 11-5). If the cylinder compression is too low, perform a leak-down test. |
| Does not crank | Perform STARTING SYSTEM TROUBLESHOOTING | |
| Engine does not start or is hard to start. | Engine lacks power. Engine will not rev sufficiently. ENGINE OIL level low. FUEL STRAINER clogged. IGNITION COIL faulty. CHARGE / POWER COIL faulty. CONTROL GEAR BOX faulty. COMBINATION SWITCH faulty. ECM faulty. SPARK ARRESTER clogged. VALVE or VALVE SEAT worn or damaged. CYLINDER, PISTON, or PISTON RING worn. WIRE HARNESS faulty. OIL LEVEL SWITCH faulty. SPARK PLUG faulty. AIR CLEANER ELEMENT clogged. CARBURETOR faulty. VALVE CLEARANCE incorrect. | |
| Engine does not stop when combination switch is turned off | Check the combination switch (page 7-7). Replace the combination switch. Check for continuity between the ignition coil 4P connector wire harness side and combination switch 2P connector wire harness side: Continuity, No continuity. | |
| Engine does not stop when engine oil level is low | Check the combination switch (page 7-7). Replace the combination switch. Check for open circuit in junction box circuit (page 7-11). Check for open circuit in the yellow wire between the oil level switch and ignition coil. | |
| Engine hard to start | Disassemble the carburetor to check for clogged ports, jets, and nozzles (page 5-10). Restart the engine. Check the control gear box (page 5-7). Remove the carburetor spacer (page 5-4) and check whether the choke valve is closed when pulling the recoil starter. | |
| Engine speed does not stabilize | Disassemble and inspect for restricted parts. Replace or repair the main wire harness. Check for continuity between the ECM 8P connector wire harness side and junction box 8P connector wire harness side: No continuity, Normal, Abnormal, Normal. |
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.