Small Engine
Honda GX120
4-Stroke
The Honda GX120 is a 118cc 4-stroke overhead-valve small engine built on Honda's GX commercial platform, powering pressure washers, water pumps, tillers, go-karts, and generators. The entry point of the GX series, it is designed for light to moderate duty applications where compact size and reliability are paramount. It uses a Keihin float-type carburetor and accepts NGK BPR6ES or Champion RC12YC spark plugs. The overhead-valve design provides superior fuel efficiency and longevity over flat-head designs. Routine maintenance: annual oil change (SAE 10W-30), air filter, and spark plug.
Honda GX120 quick specs
- Equipment
- Small Engine · 4-Stroke
- Covered Parts
- Spark Plug, Air Filter, Carburetor, Fuel Filter
- OEM References
- 4
- Model Family
- GX120, GX140, GX160, GX200
Spark Plug
OEM98079-55846(0.7-0.8mm gap)NGK BPR5ES equivalent; used in water pumps, pressure washers, tillers, and compactors
| Brand | Part # | |
|---|---|---|
| NGK | BPR5ES | Buy on Amazon → |
| Champion | RS12YC | Buy on Amazon → |
Air Filter
OEM17210-ZE0-505Paper element; also fits GX110. Superseded by 17210-ZE0-822
| Brand | Part # | |
|---|---|---|
| Stens | 100-958 | Buy on Amazon → |
Carburetor
OEM16100-ZH7-W51Keihin BE60B float-type carb; fits GX110 and GX120
| Brand | Part # | |
|---|---|---|
| Stens | 520-702 | Buy on Amazon → |
| Keihin | BE60B | Buy on Amazon → |
Fuel Filter
OEM16955-ZE1-010In-tank fuel filter/joint; fits GX series 4-13HP engines
| Brand | Part # | |
|---|---|---|
| Stens | 120-327 | Buy on Amazon → |