Generac Q-55G troubleshooting: 24 symptom-cause-remedy entries from the manufacturer's own service documentation.
Generac Q-55G — full specs, parts & maintenance.
| Symptom | Cause | Remedy |
|---|---|---|
| Engine won't crank | 15 amp fuse blown | Replace blown fuse |
| Engine won't crank | Loose, corroded or defective battery cable(s) | Tighten, clean or replace, as necessary |
| Engine won't crank | Transfer switch (if so equipped) is set to wrong position | |
| Engine won't crank | Failure in vehicle electrical system | |
| Engine won't crank | Generator component failure | |
| Engine won't crank | Battery is discharged or defective | Recharge or replace battery |
| Engine won't crank | Defective starter contactor | Replace starter contactor |
| Engine won't crank | Defective starter motor | Replace starter motor |
| Engine won't crank | Defective control relay (CR1) | Replace control relay |
| Engine cranks, won't start | Out of fuel | Refill fuel tank |
| Engine cranks, won't start | Fuel shutoff valve is closed | Open fuel shutoff valve(s) |
| Engine cranks, won't start | Fuel pump not operating | Repair or replace pump |
| Engine cranks, won't start | Automatic choke not operating properly | Repair, replace or adjust |
| Engine cranks, won't start | Engine is flooded | Wait 5-10 minutes; try again |
| Engine cranks, won't start | Fuel filter is clogged | Replace filter if clogged |
| Engine cranks, won't start | Defective control relay (CR2) | Replace bad relay (CR2) |
| Engine cranks, won't start | Engine spark plugs defective | Clean, regap or replace as needed |
| Engine cranks, won't start | Bad ignition magneto on engine | Replace if defective |
| Engine cranks, won't start | Bad carburetor | Adjust, repair or replace |
| Engine cranks, won't start | Dirty air cleaner | Clean or replace as needed |
| Engine starts hard, runs rough | Dirty engine air cleaner | Clean or replace as needed |
| Engine starts hard, runs rough | Automatic choke is sticking | Free choke linkage as needed |
| Engine starts hard, runs rough | Defective spark plugs | |
| Engine starts hard, runs rough | Defective ignition magneto |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Out of fuel; Fuel shutoff valve is closed; Fuel pump not operating; Automatic choke not operating properly. See the table for the matching fixes.
Documented causes: 15 amp fuse blown; Loose, corroded or defective battery cable(s); Transfer switch (if so equipped) is set to wrong position; Failure in vehicle electrical system. See the table for the matching fixes.
Documented causes: Dirty engine air cleaner; Automatic choke is sticking; Defective spark plugs; Defective ignition magneto. See the table for the matching fixes.