Tecumseh LH318SA-156585H engine Parts

To tell the build year of your Tecumseh engine (model LH318SA-156585H), we use the engine’s identification numbers stamped on the shroud or printed on an ID label. Once you find the model, spec, and serial or date code, the first digits typically map to the production date and year.

Where to find the Tecumseh ID numbers

On most Tecumseh lawn and garden engines, the ID is in one of these spots:

• Blower housing (air shroud) near the spark plug
• Recoil starter housing area
• Under or near the carburetor mounting area
• On a metal tag or sticker on the shroud
• Stamped directly into the sheet metal (not a removable decal)

If you are already working around the fuel system, replacing a leaking carburetor seal like the lawn mower o-ring 631028A can be a good time to clean the shroud and make the stamp easier to read.

How to decode the year from the code

Tecumseh commonly uses a combination of:

• Model number (example: LH318SA)
• Spec number (a build configuration)
• Serial number or date of manufacture (D.O.M.) code

What the code usually tells you

What you find	What it’s used for	What to record
Model number	Engine family and basic design	Full model (letters and numbers)
Spec number	Exact carburetor, ignition, governor setup	Spec exactly as printed
Serial or D.O.M. code	Production date range and year	Entire string, in order

Many Tecumseh date codes start with digits that represent the production date (often day and year information). Record the full code first; then compare the leading digits to Tecumseh date-code formats to identify the year.

Tips to avoid misreading the stamp

• Wipe the area with degreaser; then use a flashlight at a low angle
• Chalk or a wax pencil over the stamp helps the characters stand out
• Write down the code twice; compare for look-alike characters (5/S, 0/O, 1/I)

Why it matters

The year and spec determine which carburetor, ignition module, and gaskets your LH318SA-156585H uses. That prevents ordering the wrong tune-up or fuel-system parts, especially when Tecumseh made mid-year changes.

Last updated: February 2026

The Tecumseh LH318SA-156585H is a 9 HP horizontal-shaft lawn and garden engine (often listed under the LH318SA Snow King family). If you are matching an engine to equipment, horsepower is only one fit factor; shaft size, mounting pattern, and carburetor setup matter just as much.

Quick specs to confirm before you buy parts

To avoid ordering the wrong carburetor, starter, or ignition parts for your LH318SA-156585H, we recommend checking these items on your engine:

• Shaft diameter and length (critical for pulleys and drive systems)
• Shaft keyway size (if your application uses a keyed shaft)
• Starter type (recoil vs. electric start)
• Carburetor style (linkage and choke arrangement)
• Ignition/kill wire setup (stop switch wiring)

Parts that commonly relate to performance and power complaints

If the engine feels weak, surges, or will not hold RPM, the issue is usually fuel delivery, air restriction, or ignition, not the horsepower rating itself. These model-matched parts are common fixes:

• Craftsman lawn & garden equipment engine carburetor 640349
• Tecumseh lawn and garden equipment engine carburetor rebuild kit 632760B
• Craftsman lawn & garden equipment engine air filter 28424
• Needle valve 631021B
• Craftsman lawn & garden equipment engine fuel tank cap 37845

What “9 HP” means in real use

Horsepower is a general output rating; real-world performance depends heavily on tune and load. A partially clogged carburetor, restricted air filter, or a venting fuel cap can make a 9 HP engine behave like a much smaller one.

Symptom	Most common cause	Part to check first
Surging at idle	Dirty carb circuits	Tecumseh lawn and garden equipment engine carburetor rebuild kit 632760B
Runs then dies	Fuel cap not venting or fuel restriction	Craftsman lawn & garden equipment engine fuel tank cap 37845
Black smoke, rich running	Carb flooding or needle not sealing	Needle valve 631021B
Low power under load	Restricted airflow	Craftsman lawn & garden equipment engine air filter 28424

Why it matters

Using the correct horsepower rating helps you choose an appropriate replacement engine, but using the correct LH318SA-156585H parts list is what keeps the engine starting easily, running smoothly, and producing full power.

Last updated: February 2026

Tecumseh engines like model LH318SA-156585H usually get hard to start when fuel delivery or airflow is restricted (stale fuel varnish in the carburetor, plugged vent, dirty filter) or when ignition and cranking components are weak. A quick fuel, air, and spark check solves most “hard pull” and “won’t fire” complaints.

Most common causes (and what to check first)

• Old fuel: Drain the tank and carburetor bowl; refill with fresh fuel.
• Carburetor varnish or debris: If it starts only with choke or dies under throttle, the carb is restricted.
• Dirty air filter: A clogged filter can make starting erratic and cause rich running.
• Fuel cap vent restriction: A plugged vent creates vacuum in the tank and starves the carb.
• Worn carb seals or needle issues: Leaks or poor metering can cause flooding or lean starts.
• Weak ignition or kill circuit issue: A grounded stop wire can prevent spark.

Quick troubleshooting steps (10 to 15 minutes)

1. Try fresh fuel and confirm the fuel shutoff (if equipped) is open.
2. Check the air filter; replace if dirty using the craftsman lawn & garden equipment engine air filter 28424.
3. Loosen the fuel cap and try starting; if it improves, replace the cap or vent using the craftsman lawn & garden equipment engine fuel tank cap 37845.
4. Inspect the stop wire for chafing or a loose terminal; repair as needed (the craftsman lawn & garden equipment engine stop wire terminal 610973 is a common fix).
5. If it still will not start reliably, service the carburetor (clean or rebuild).

Carburetor service: rebuild kit vs replacement

If the engine surges, only runs on choke, or floods easily, carburetor service is the next best step.

Symptom	Most likely carb issue	Best next step
Starts then dies	Restricted main jet/passages	Rebuild with Tecumseh lawn and garden equipment engine carburetor rebuild kit 632760B
Hard start after storage	Varnish in passages	Rebuild kit or full carb replacement
Fuel dripping, plug wet	Needle not sealing	Replace needle using needle valve 631021B
Persistent problems	Worn carb body or damage	Replace with craftsman lawn & garden equipment engine carburetor 640349

Why it matters

Hard starting is usually a warning that the engine is running too lean, too rich, or not getting consistent spark. Fixing the root cause prevents repeated rope pulls, plug fouling, and premature wear on the starter system.

Last updated: February 2026

On a Tecumseh engine model like LH318SA-156585H, “318” is typically part of the engine’s model/series identification (often pointing to an approximate engine size class and design family), not a universal code with a single meaning across all products.

Where you’ll see “318” on this engine

On Tecumseh lawn and garden engines, the “318” most often shows up as part of the model string (for example, LH318SA) and is used to match the correct parts list.

• It helps narrow down the correct carburetor, gaskets, and fuel system parts
• It distinguishes this engine family from similar Tecumseh models
• It matters when ordering tune-up and carburetor parts
• It is not an error code or a maintenance interval

Why it matters for parts lookup

Small-engine parts are model-specific; using the full model number LH318SA-156585H prevents ordering the wrong carburetor or seals.

Common “match-by-model” parts for this engine include:

• Craftsman lawn & garden equipment engine carburetor 640349
• Tecumseh lawn and garden equipment engine carburetor rebuild kit 632760B
• Needle valve 631021B
• Craftsman lawn & garden equipment engine carburetor o-ring 632547

Quick guide: model/series vs. part numbers

Item type	Example on this engine	What it’s used for
Engine model/series	LH318SA	Identifies the engine family/design
Full engine model spec	LH318SA-156585H	Exact parts breakdown for your engine
Part ID	640349	Identifies a specific replacement part listing
Part number	640349	Manufacturer number for the part

If you’re trying to solve a running problem

If the engine is hard-starting, surging, or leaking fuel, the “318” itself is not the cause; it just helps us pick the right fuel-system parts.

• Replace a dirty air filter (example: craftsman lawn & garden equipment engine air filter 28424)
• Check for fuel varnish and stuck float/needle
• Inspect carburetor O-rings for air leaks
• Consider a rebuild kit if the carburetor is gummed up

Why it matters

Using the correct Tecumseh model identification reduces mis-orders and speeds up repairs, especially for carburetor and gasket-related issues.

Last updated: February 2026

Yes. For the Tecumseh LH318SA-156585H lawn and garden engine, synthetic oil is a normal, safe choice when you match the viscosity to your operating temperatures and keep the oil at the full mark; 5W-30 synthetic is a common all-season option for many 4-cycle small engines.

Choose the right oil for your conditions

Use 4-cycle small-engine oil (not 2-cycle mix oil) and pick viscosity based on temperature.

• 5W-30 synthetic: best for cold starts and wide temperature swings
• SAE 30: best for steady warm-weather mowing
• 10W-30: good for moderate temperatures and mixed use
• Keep the oil level correct; overfilling can cause smoking and leaks

Quick viscosity guide (typical small-engine use)

Operating conditions	Common viscosity	Typical benefit
Cold starts, variable temps	5W-30 synthetic	Easier starting, smoother cranking
Mostly warm weather	SAE 30	Strong hot-weather protection
Mild to warm, mixed use	10W-30	Versatile day-to-day option

If the engine smokes after switching to synthetic

Smoking after an oil change usually points to oil level, air flow, or engine wear.

• Verify oil level on a level surface; drain to the correct mark if overfilled
• Check the air filter; restricted air flow can increase oil pull-over (see craftsman lawn & garden equipment engine air filter 28424)
• Look for oil in the air box or breather tube (often tied to overfill or blow-by)
• If smoking continues, switch to SAE 30 and monitor oil consumption

Why it matters

Correct viscosity protects internal parts like the crankshaft and bearings, improves starting, and reduces wear. Synthetic oil can improve cold-start lubrication, but a worn engine may show smoke sooner, so monitoring oil level and consumption is important.

Last updated: February 2026