Chainsaw

Echo CS-310

2-Stroke

The Echo CS-310 is a 30.5cc 2-stroke chainsaw and the entry-level model in Echo's consumer CS lineup. Designed for light homeowner work — limbing, small firewood, and storm cleanup — it accepts 12" to 14" guide bars. The CS-310 runs a Zama carburetor, consistent with most Echo consumer equipment, and features tool-less air filter access for quick field maintenance. Common service items are the air filter, fuel filter, primer bulb, and fuel lines. Echo's purge bulb design simplifies cold starting. A solid entry point for homeowners who want a dedicated brand rather than a big-box-store equivalent.

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: Chainsaw · 2-Stroke
Covered Parts: Spark Plug, Air Filter, Fuel Filter, Carburetor, Recoil Starter, Primer Bulb, Fuel Line Kit, Chain, Guide Bar
OEM References: 90023Y, A226000200, A369000100, 12520005964, A180001090, 12318139130, V471001471
Model Family: CS-310, CS-352
Last Reviewed: Not yet independently reviewed
Data Confidence: Not yet independently reviewed
Sources Consulted: Evidence source not recorded

Quick Fitment

Part Type	OEM / Spec	Common Option	Confidence
Spark Plug	90023Y	Champion CJ8Y	Confidence not assigned · Not yet independently reviewed
Air Filter	A226000200	Stens 605-266	Confidence not assigned · Not yet independently reviewed
Fuel Filter	A369000100	Stens 610-009	Confidence not assigned · Not yet independently reviewed
Carburetor	12520005964	Zama C1M-K37B	Confidence not assigned · Not yet independently reviewed
Primer Bulb	12318139130	Zama BG-00-4	Confidence not assigned · Not yet independently reviewed
Recoil Starter	A180001090	OEM A180001090	Confidence not assigned · Not yet independently reviewed
Fuel Line Kit	V471001471	Stens 115-530	Confidence not assigned · Not yet independently reviewed
Chain	14", 3/8" LP pitch, .050" gauge, 52 drive links	Oregon 91PX052G	Confidence not assigned · Not yet independently reviewed

Tune-Up Kit

Common service bundle: spark plug, air filter, fuel filter, carburetor, primer bulb, fuel line kit.

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 Echo CS-310, 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.
Assuming all fuel line kits use the same diameter and routing.
Installing the correct plug number with the wrong gap.
Matching bar length but missing pitch, gauge, or drive-link count.

Symptoms Map

Won't start

Spark plug, fuel filter, primer bulb, carburetor

Starts then dies

Fuel filter, fuel line kit, carburetor

Bogs under throttle

Air filter, carburetor, spark plug gap

Primer will not fill

Primer bulb, fuel line routing, in-tank filter

Cuts slowly

Chain pitch/gauge, bar wear, drive links

Replacement Options

Best OEM equivalent

Start with OEM references 90023Y, A226000200, A369000100, 12520005964 and match the removed part before choosing a listing.

Common aftermarket option

Cross-check aftermarket listings such as Champion CJ8Y (spark plug), Stens 605-266 (air filter), Stens 610-009 (fuel filter) against the OEM number and dimensions.

Best for annual tune-up

Bundle spark plug, air filter, fuel filter when servicing the Echo CS-310 at the start of the season.

Best if replacing fuel system

Compare the fuel filter, carburetor, primer bulb, fuel line kit together so line routing, bulb size, filter style, and carburetor connections match.

Best chain/bar combo

Match chain specs together, especially pitch, gauge, drive links, and bar mount details.

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

Should I buy OEM or aftermarket parts for the Echo CS-310? 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 CS-310? 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.

What chain details matter besides bar length? Match pitch, gauge, and drive-link count against the bar stamp, old chain, and drive sprocket. Bar length alone is not enough.

Spark Plug

OEM90023YConfidence: Confidence not assigned · Source: Evidence source not recorded

Reviewed: Not yet independently reviewed
Dimensions: 0.6mm gap
Variant notes: Also fits CS-352, CS-355T

Brand	Part #
Champion	CJ8Y	Search AmazonAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.
NGK	BPM8Y	Search AmazonAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Air Filter

OEMA226000200Confidence: Confidence not assigned · Source: Evidence source not recorded

Reviewed: Not yet independently reviewed
Variant notes: Also fits CS-352, CS-355T

Brand	Part #
Stens	605-266	Search AmazonAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Fuel Filter

OEMA369000100Confidence: Confidence not assigned · Source: Evidence source not recorded

Reviewed: Not yet independently reviewed
Variant notes: In-tank pickup filter; fits most Echo chainsaws and trimmers

Brand	Part #
Stens	610-009	Search AmazonAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Carburetor

OEM12520005964Confidence: Confidence not assigned · Source: Evidence source not recorded

Reviewed: Not yet independently reviewed
Variant notes: Zama C1M-K37B; 30.5cc engine

Brand	Part #
Zama	C1M-K37B	Search AmazonAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Recoil Starter

OEMA180001090Confidence: Confidence not assigned · Source: Evidence source not recorded

Reviewed: Not yet independently reviewed
Variant notes: Also fits CS-352

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.

Primer Bulb

OEM12318139130Confidence: Confidence not assigned · Source: Evidence source not recorded

Reviewed: Not yet independently reviewed

Brand	Part #
Zama	BG-00-4	Search AmazonAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Fuel Line Kit

OEMV471001471Confidence: Confidence not assigned · Source: Evidence source not recorded

Reviewed: Not yet independently reviewed
Variant notes: Includes fuel pickup line and return line

Brand	Part #
Stens	115-530	Search AmazonAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Chain

OEMSpec-based fitmentConfidence: Confidence not assigned · Source: Evidence source not recorded

Reviewed: Not yet independently reviewed
Dimensions: 14", 3/8" LP pitch, .050" gauge, 52 drive links
Variant notes: Stock bar length; verify drive link count matches your bar

Brand	Part #
Oregon	91PX052G	Search AmazonAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Guide Bar