WhichPartFits.com

Chainsaw

Echo CS-400

2-Stroke

The Echo CS-400 is a 40.2cc 2-stroke chainsaw and one of Echo's most popular homeowner/prosumer models, capable of handling 16" to 18" guide bars for regular firewood and moderate felling. It runs a Zama C1M carburetor and features a large-capacity air filtration system. Known for reliable cold starting and ease of routine maintenance. Common service items are the spark plug (Champion CJ8Y), air filter, fuel filter, and primer bulb. Echo's G-Force Engine Air Pre-Cleaner system extends air filter service intervals compared to conventional filtration designs.

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

Echo CS-400 quick specs

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, A226000860, A369000100, 12520005570, A180001210, 12318139130, 13200700760
Model Family
CS-400, CS-440
Data Confidence
Not yet independently reviewed

Quick Fitment

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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-400, 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, A226000860, A369000100, 12520005570 and match the removed part before choosing a listing.

Named part options

Cross-check named parts such as Champion CJ8Y (spark plug), Stens 605-400 (air filter), Stens 610-009 (fuel filter) against the OEM number, identity label, and dimensions.

Best for annual tune-up

Bundle spark plug, air filter, fuel filter when servicing the Echo CS-400 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-400? 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-400? 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.

As an Amazon Associate, WhichPartFits earns from qualifying purchases. Match the OEM number, dimensions, and model variant before buying.

Spark Plug

OEM90023Y
Dimensions
0.6mm gap

Air Filter

OEMA226000860

Fuel Filter

OEMA369000100
Variant notes
In-tank pickup filter; fits most Echo chainsaws and trimmers

Carburetor

OEM12520005570
Variant notes
Zama C1M-K47B; 40.2cc engine

Recoil Starter

OEMA180001210
  • No named part listing is published for this part yet. Use the OEM reference and verify with a dealer or service manual before ordering.

Primer Bulb

OEM12318139130

Fuel Line Kit

OEM13200700760
Variant notes
Includes fuel pickup line and return line

Chain

OEMSpec-based fitment
Dimensions
18", 3/8" LP pitch, .050" gauge, 62 drive links
Variant notes
Stock bar length; verify drive link count matches your bar

Guide Bar

OEMSpec-based fitment
Dimensions
18", 3/8" LP pitch, .050" gauge