Small Engine

Honda GX270

4-Stroke

The Honda GX270 is a 270cc 4-stroke overhead-valve engine used in mid-range pressure washers, generators, water pumps, and plate compactors requiring more power than the GX200. It uses a Keihin float-type carburetor and accepts NGK BPR6ES or Champion RC12YC spark plugs. The displacement step up from the GX200 produces meaningfully more torque for driving hydraulic pumps and large-impeller water pumps. Routine maintenance every 100 hours includes oil change (SAE 10W-30), air filter service, and spark plug inspection. The governor linkage and throttle spring are inspection items on high-hour GX270s in pressure washer service.

See a wrong fitment? Report a correction.

Verify before ordering: Fitment can vary by serial number, production date, region, and sub-model. Match the OEM number and physical dimensions before ordering.

Equipment: Small Engine · 4-Stroke
Covered Parts: Spark Plug, Air Filter, Carburetor, Recoil Starter, Ignition Coil
OEM References: 98079-56846, 17210-ZE2-505, 16100-ZH9-W51, 28400-ZE3-003ZA, 30500-ZH7-003ZA
Model Family: GX240, GX270
Last Reviewed: 2026-05-20
Data Confidence: Aftermarket-confirmed
Sources Consulted: OEM part references, Aftermarket catalog cross-references, Retailer fitment listings

ℹ See also: GX240 — parts are often interchangeable within this family.

Quick Fitment

Part Type	OEM / Spec	Common Option	Confidence
Spark Plug	98079-56846	NGK BPR6ES	Medium · 2026-05-20
Air Filter	17210-ZE2-505	Stens 102-414	Medium · 2026-05-20
Carburetor	16100-ZH9-W51	Keihin BB-51	Medium · 2026-05-20
Recoil Starter	28400-ZE3-003ZA	Stens 150-471	Medium · 2026-05-20
Ignition Coil	30500-ZH7-003ZA	OEM 30500-ZH7-003ZA	Low · 2026-05-20

Tune-Up Kit

Common service bundle: spark plug, air filter, carburetor.

Maintenance Interval

Inspect filters and fuel lines each season, replace spark plugs during annual service, and service carb/fuel-system parts when starting or idle symptoms appear.

Before You Buy

Confirm the full model is Honda GX270, not just the family name.
Check serial number, production date, and regional variant before ordering.
Match the old OEM number stamped on the removed part when available.
Compare dimensions, plug gap, thread, fuel line diameter, or chain pitch/gauge where applicable.

Common Mistakes

Ordering from a family listing without checking the exact sub-model.
Buying a kit that includes the headline part but wrong gaskets, lines, or bulb size.
Choosing the wrong carburetor revision when multiple versions were used.
Installing the correct plug number with the wrong gap.

Symptoms Map

Won't start

Spark plug, fuel filter, primer bulb, carburetor

Bogs under throttle

Air filter, carburetor, spark plug gap

Replacement Options

Best OEM equivalent

Start with OEM references 98079-56846, 17210-ZE2-505, 16100-ZH9-W51, 28400-ZE3-003ZA and match the removed part before choosing a listing.

Common aftermarket option

Cross-check aftermarket listings such as NGK BPR6ES (spark plug), Stens 102-414 (air filter), Keihin BB-51 (carburetor) against the OEM number and dimensions.

Best for annual tune-up

Bundle spark plug, air filter when servicing the Honda GX270 at the start of the season.

Best budget kit

Use kit listings only when every included part matches this model page; cheap kits often mix correct headline parts with wrong bulbs, lines, or gaskets.

FAQ

Does this fit GX240? Parts may interchange with GX240, but verify the serial range, OEM number, and physical part details before ordering.

Should I buy OEM or aftermarket parts for the Honda GX270? Use OEM when the part controls fuel metering, ignition, or safety. Aftermarket kits can be useful for routine filters, bulbs, plugs, and tune-up bundles when the OEM number and dimensions match.

How do I avoid ordering the wrong carburetor for the GX270? Match the carburetor number stamped on the removed unit, then compare linkage, choke setup, primer routing, gasket stack, and fuel-inlet direction.

What should I check before replacing fuel-system parts? Photograph the old fuel-line routing, match line diameter and filter style, and compare primer bulb size before buying a kit.

Spark Plug

OEM98079-56846Confidence: Medium · Source: Aftermarket catalog

Reviewed: 2026-05-20
Dimensions: 0.7mm gap
Variant notes: BPR6ES; same plug used across GX160, GX200, GX270, GX340, GX390

Brand	Part #
NGK	BPR6ES	Best for annual tune-upAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.
Champion	RC12YC	Best for annual tune-upAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Air Filter

OEM17210-ZE2-505Confidence: Medium · Source: Aftermarket catalog

Reviewed: 2026-05-20
Variant notes: Paper element; also fits GX240

Brand	Part #
Stens	102-414	Best for annual tune-upAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Carburetor

OEM16100-ZH9-W51Confidence: Medium · Source: Aftermarket catalog

Reviewed: 2026-05-20
Variant notes: Keihin BB-51 float-type carb; also fits GX240

Brand	Part #
Keihin	BB-51	Best if replacing fuel systemAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Recoil Starter

OEM28400-ZE3-003ZAConfidence: Medium · Source: Aftermarket catalog

Reviewed: 2026-05-20
Variant notes: Also fits GX240

Brand	Part #
Stens	150-471	Best overallAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Ignition Coil

OEM30500-ZH7-003ZAConfidence: Low · Source: Aftermarket catalog

Reviewed: 2026-05-20

Brand	Part #
No aftermarket listing is published for this part yet. Use the OEM reference and verify with a dealer or service manual before ordering.