Chainsaw

Husqvarna 120

2-Stroke

The Husqvarna 120 is a 38.2cc 2-stroke chainsaw positioned as an occasional-use homeowner model for light property tasks — limbing, small firewood, and storm cleanup — accepting 13" to 15" guide bars. It runs a Zama carburetor. Husqvarna's SmartStart system reduces initial pull resistance. The 120 shares service part families with the 130 series for good parts availability. Routine maintenance items are the spark plug (NGK BPMR7A or Champion RCJ6Y), air filter, primer bulb, and fuel lines. Draining the fuel system before storage prevents the most common no-start condition on low-use homeowner saws.

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, Ignition Coil, Primer Bulb, Fuel Line Kit, Chain, Guide Bar
OEM References: 503235108, 545061801, 591375401, 586936202, 545008028, 575803501, 545008030, 580727101
Model Family: 120, 130, 135
Last Reviewed: 2026-05-21
Data Confidence: Aftermarket-confirmed
Sources Consulted: Husqvarna 120 parts references, Aftermarket catalog cross-references, Retailer fitment listings

ℹ See also: 130, 135 — parts are often interchangeable within this family.

Quick Fitment

Part Type	OEM / Spec	Common Option	Confidence
Spark Plug	503235108	NGK BPMR7A	Medium · 2026-05-21
Air Filter	545061801	Stens 605-580	Medium · 2026-05-21
Fuel Filter	591375401	Stens 610-034	Medium · 2026-05-21
Carburetor	586936202	Zama C1T-W33C	Medium · 2026-05-21
Primer Bulb	545008030	Zama BG-00-4	Medium · 2026-05-21
Recoil Starter	545008028	OEM 545008028	Low · 2026-05-21
Ignition Coil	575803501	OEM 575803501	Low · 2026-05-21
Fuel Line Kit	580727101	Stens 115-530	Medium · 2026-05-21

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 Husqvarna 120, 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 503235108, 545061801, 591375401, 586936202 and match the removed part before choosing a listing.

Common aftermarket option

Cross-check aftermarket listings such as NGK BPMR7A (spark plug), Stens 605-580 (air filter), Stens 610-034 (fuel filter) against the OEM number and dimensions.

Best for annual tune-up

Bundle spark plug, air filter, fuel filter when servicing the Husqvarna 120 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

Does this fit 130 or 135? Parts may interchange with 130, 135, but verify the serial range, OEM number, and physical part details before ordering.

Should I buy OEM or aftermarket parts for the Husqvarna 120? 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 120? 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.

Related Repair Guides

Husqvarna 120 Starts Then Dies: Fuel and Air ChecksA troubleshooting guide for Husqvarna 120 chainsaws that start briefly and stall, with links to filters, fuel line kits, carburetor, and spark plug references.How to Measure Chainsaw Chain Pitch, Gauge, and Drive LinksA model-identification guide for chainsaw chain replacement, explaining why bar length alone is not enough.Oregon Chain Number GuideHow to use Oregon chain numbers with pitch, gauge, drive-link count, bar length, and sprocket compatibility.

Spark Plug

OEM503235108Confidence: Medium · Source: Aftermarket catalog

Reviewed: 2026-05-21
Dimensions: 0.5mm gap
Variant notes: NGK BPMR7A; fits 120 Mark II

Brand	Part #
NGK	BPMR7A	Best for annual tune-upAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.
Champion	RCJ6Y	Best for annual tune-upAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Air Filter

OEM545061801Confidence: Medium · Source: Aftermarket catalog

Reviewed: 2026-05-21
Variant notes: Also fits 120 Mark II, 230, 235, 236, 240

Brand	Part #
Stens	605-580	Best for annual tune-upAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Fuel Filter

OEM591375401Confidence: Medium · Source: Aftermarket catalog

Reviewed: 2026-05-21
Variant notes: In-tank pickup filter

Brand	Part #
Stens	610-034	Best if replacing fuel systemAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Carburetor

OEM586936202Confidence: Medium · Source: Aftermarket catalog

Reviewed: 2026-05-21
Variant notes: 14mm air bore; also fits 120 Mark II, 235, 236, 240 (C1T-W33C type)

Brand	Part #
Zama	C1T-W33C	Best if replacing fuel systemAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Recoil Starter

OEM545008028Confidence: Low · Source: Aftermarket catalog

Reviewed: 2026-05-21
Variant notes: Standard starter kit; also fits 120 Mark II, 235, 236, 240

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.

Ignition Coil

OEM575803501Confidence: Low · Source: Aftermarket catalog

Reviewed: 2026-05-21
Variant notes: Also fits 120 Mark II, 136, 141, 230, 235, 236, 240

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

OEM545008030Confidence: Medium · Source: Aftermarket catalog

Reviewed: 2026-05-21
Variant notes: Purge and line assembly; also fits 120 Mark II, 125B, 235, 236, 240

Brand	Part #
Zama	BG-00-4	Best if replacing fuel systemAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Fuel Line Kit

OEM580727101Confidence: Medium · Source: Aftermarket catalog

Reviewed: 2026-05-21
Variant notes: Fuel hose kit LP100 5.3 O.D.; includes main fuel line

Brand	Part #
Stens	115-530	Best if replacing fuel systemAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Chain

OEMSpec-based fitmentConfidence: Low · Source: Inferred

Reviewed: 2026-05-21
Dimensions: 16 inch, 3/8 inch LP pitch, .050 inch gauge, 56 drive links
Variant notes: Stock bar length; verify drive link count matches your bar

Brand	Part #
Oregon	91PX056G	Best chain/bar comboAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.
Oregon	S56	Best chain/bar comboAmazonAffiliate link Some links may be affiliate links. Match the OEM number, dimensions, and model variant before buying.

Guide Bar