The Cummins/Onan GH170 is a 0.17 L engine rated at 3600 rpm. It powers generator sets from Cummins/Onan, including the 2.0 EGHAM and 2.5 EGHAA. It holds 0.63 L (0.2 gal) of oil.
Also known as: Cummins GH170
| Oil capacity | 0.63 L |
|---|---|
| Displacement | 0.169 L |
| Rated speed | 3600 rpm |
| Symptom | Cause | Remedy |
|---|---|---|
| Engine misfires | Worn or fouled spark plug | Clean or replace spark plug |
| Lean fuel mixture | Incorrectly adjusted carburetor | See Carburetor Adjustment section |
| Contaminated fuel | Drain fuel tank and refill with fresh fuel | |
| Dirty air cleaner | Clean or replace air cleaner | |
| Backfires | Worn or fouled spark plug | Clean or replace spark plug |
| Excessive engine wear | E140H engine: See Onan Elite Horizontal engine manual 965-0758 GH170, GH280 engines: See Engine Block Assembly section | |
| Restricted fuel flow | Plugged fuel filter | Clean or replace fuel filter |
| Incorrect fuel mixture | Incorrectly adjusted carburetor | See Carburetor Adjustment section |
| Exhaust system blocked or restricted | Locate and remove cause of blockage | |
| Incorrect valve clearance or defective valve(s) | E140H engine: See Onan Elite Horizontal engine manual 965-0758 GH170, GH280 engines: See Engine Block Assembly section | |
| No load speed set too low | Adjust governor setting | |
| Excessive engine wear or damage to engine | E140H engine: See Onan Elite Horizontal engine manual 965-0758 GH170, GH280 engines: See Engine Block Assembly section | |
| Restricted air flow | Dirt or debris blocking air inlet or outlet | Clear away any debris that may restrict airflow |
| Dirt or oil covering engine cooling fins | Clean away all dirt and oil from engine cooling fins | |
| Cooling fan plugged or broken | Inspect cooling fan, see Generator Service section | |
| Clogged or faulty breather | Clean or replace breather | |
| Black exhaust smoke | Dirty air cleaner | Clean or replace air cleaner |
| White or blue exhaust smoke | Dirty air cleaner | Clean or replace air cleaner |
| Engine Backfires | Faulty ignition due to: a. worn or fouled spark plug; b. faulty ignition system; Lean fuel mixture due to: a. incorrectly adjusted carburetor; b. incorrect float level; c. dirt in carburetor; d. vacuum leak; | A. Clean or replace spark plug. b. See Ignition System section. c. Check spark plug wire and replace if necessary. a. See Carburetor Adjustment section. b. Check carburetor float. c. Disassemble carburetor and clean all internal passages. |
| Engine Lacks Power | Faulty ignition due to: a. worn or fouled spark plug; b. faulty ignition system; Dirty air cleaner; Restricted fuel flow due to plugged fuel filter; Incorrect fuel mixture due to: a. incorrectly adjusted carburetor; b. incorrect float level; c. dirt in carburetor; Lean fuel mixture due to: a. incorrectly adjusted carburetor; b. incorrect float level; c. dirt in carburetor; d. vacuum leak; Exhaust system blocked or restricted; Incorrect valve clearance; No load speed set too low; Excessive engine wear or damage to engine; Choke valve blockage or choke lever set incorrectly; | A. Clean or replace spark plug. b. See Ignition System section. c. Clean or replace air cleaner. d. Clean or replace fuel filter. e. a. See Carburetor Adjustment section. b. Check carburetor float. c. Disassemble carburetor and clean all internal passages. f. Locate and remove cause of blockage. g. Adjust valve clearance/inspect valves (see Engine Block Assembly section). h. Adjust governor setting. i. See Engine Block Assembly section. j. Open choke lever fully, if problem continues see fuel System section. |
| Engine Overheats | Restricted air flow due to dirt or debris blocking air inlet or outlet; Dirt or oil covering engine cooling fins; Cooling fan plugged or broken; Lean fuel mixture due to: a. incorrectly adjusted carburetor; b. incorrect float level; c. dirt in carburetor; | A. Clear away any debris that may restrict airflow. b. Clean away all dirt and oil from engine cooling fins. c. Inspect cooling fan, see Generator Service section. d. a. See Carburetor Adjustment section. b. Check carburetor float. c. Disassemble carburetor and clean all internal passages. |
| Engine Hunts or Surges | Sticking or binding governor linkage; Incorrect governor adjustment; Faulty governor spring; Incorrect fuel mixture due to: a. incorrectly adjusted carburetor; b. incorrect float level; c. dirt in carburetor; Governor mechanism worn excessively; Fuel supply problem caused by: a. Dirty fuel filter; b. Contaminated fuel supply; | A. Clean or replace air cleaner. b. Check choke setting. c. See Carburetor Adjustment section. d. Disassemble carburetor and clean all internal passages. e. Adjust valve clearance/inspect valves (see Engine Block Assembly section). f. Adjust governor setting. g. See Engine Block Assembly section. h. Open choke lever fully, if problem continues see fuel System section. |
Fault codes and symptom→remedy steps extracted from this engine’s service/owner documentation; verify against the official manual before servicing.
Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan GH170.
Step-by-step procedures compiled from the Cummins/Onan service manual for this engine.
The Cummins/Onan GH170 engine has an oil capacity of 0.63 liters.
The Cummins/Onan GH170 has a displacement of 0.169 liters.
The Cummins/Onan GH170 powers 2 generator set(s), including Cummins/Onan 2.0 EGHAM, Cummins/Onan 2.5 EGHAA.
A commonly reported issue on generators using the Cummins/Onan GH170 is: UNIT RUNS THEN SURGES. Cause: 1. Loose or worn spark plug lead 2. Faulty spark plug. 3. Dirty fuel filter or generator set at too steep of an angle. 4. Governor out of adjustment or lean fuel mixture.. Fix: 1. Check spark plug lead connection. 2. Remove and clean or replace. 3. Check fuel filter and angle of generator set. 4. Contact an Onan service center..