Match Your Engine Model to the Correct Air Filter

Briggs and Stratton engines use different air filters depending on the engine series, displacement, and year of manufacture. The manufacturer publishes filter charts organized by engine type — vertical shaft, horizontal shaft, and specialty engines — so you can find the exact part number for your machine. You do not need to guess or buy a universal filter; the correct one is documented and usually inexpensive.

The fastest way to identify your engine is to locate the model and type number stamped or embossed on the engine block itself, usually on a metal plate near the top or side. Write down the full number — it typically looks like "12T602-0643-E1" or similar. Once you have that, you can cross-reference it against Briggs and Stratton's official filter charts, which are organized by engine family and displacement range.

If you cannot find the model number on the engine, check the equipment's original manual or the manufacturer's website for your specific mower, generator, or pressure washer. The equipment maker lists the Briggs and Stratton engine model in their documentation, which you can then use to find the air filter.

Key Takeaways

  • Locate your engine's model and type number on the metal plate attached to the engine block, then use that number to find the correct filter in Briggs and Stratton's official charts.
  • Air filter part numbers vary by engine series (Intek, Vanguard, Professional, etc.), so using the wrong filter can reduce engine performance and increase maintenance costs.
  • Briggs and Stratton publishes separate filter charts for vertical-shaft engines (used in walk-behind mowers) and horizontal-shaft engines (used in tillers and generators).
  • Most residential mowers use either the 491588 or 491588S filter, but your specific engine may require a different part number, so verification is necessary before purchase.

How Briggs and Stratton Organizes Filter Charts

Briggs and Stratton groups its air filters by engine family and displacement. The main categories are Intek (single-cylinder, consumer-grade), Vanguard (commercial and industrial), Professional (mid-range commercial), and specialty engines for specific applications. Within each family, filters are sorted by displacement in cubic centimeters (cc) or cubic inches (ci).

The company publishes these charts on its official website and in printed service manuals. You can access them through Briggs and Stratton's parts lookup tool, which allows you to enter your engine model number and returns the correct filter part number, along with cross-references to OEM equivalents from other manufacturers. This tool is free and does not require registration.

If you are working with an older engine manufactured before 2000, you may need to consult a printed manual or contact a Briggs and Stratton dealer, because some very old model numbers are not in the online database. Dealers can look up discontinued engines by phone or email using the model number.

Common Air Filter Part Numbers and What Engines They Fit

The most commonly used Briggs and Stratton air filter for residential lawn mowers is the 491588, a foam-element filter that fits many Intek engines in the 3.5 to 6.5 horsepower range. A related part, the 491588S, is a similar foam filter used in slightly different engine configurations. Neither is universal — they fit specific engine families — but they appear in a large number of consumer mowers.

For larger residential or commercial engines, the 798897 is a pleated-paper filter used in Vanguard and Professional series engines. The 593260 is a foam filter for certain Intek models. For vertical-shaft engines in walk-behind mowers, the 491588 and 491588S remain the most common, but some models use the 798897 or other variants.

Do not assume your mower uses one of these three part numbers. Briggs and Stratton manufactures dozens of filter types, and using the wrong one can restrict airflow, cause the engine to run rich (too much fuel, not enough air), or allow unfiltered dirt into the carburetor. Always verify the part number for your specific engine before purchasing.

Reading the Filter Chart: Model Number to Part Number

To use a Briggs and Stratton filter chart, start with your engine's model number. Look for the row that matches your model, then read across to the "Air Filter" column. The part number listed there is the one you need. Some charts include multiple columns — one for the primary filter, one for a secondary or backup filter, and one for foam pre-filters used in dusty conditions.

Charts are typically organized by engine series first (Intek, Vanguard, etc.), then by displacement or model range. For example, a chart might show "Intek 3.5–6.5 cc" as a heading, with individual model numbers listed below. Find your model in that range, then read the corresponding filter part number.

If your engine model appears in multiple rows or under multiple series headings, cross-check the displacement (cc or ci) and year range to make sure you are reading the correct line. A model number like "12T602" might have variants across different years, and each variant may use a different filter.

Where to Find Official Briggs and Stratton Filter Charts

The primary source is Briggs and Stratton's official website, which hosts a parts lookup tool and downloadable PDF charts. You can search by engine model number, and the tool returns the correct filter part number along with other maintenance items like spark plugs and oil capacity. The tool is free and updated regularly as new engines are released.

Authorized Briggs and Stratton dealers also have access to complete filter charts and can look up your engine by model number over the phone or in person. If you have the equipment manual (for your mower, generator, or other machine), it usually lists the engine model and the correct filter part number in the maintenance section.

Some equipment manufacturers, like Toro, Craftsman, and MTD, publish their own filter charts that cross-reference Briggs and Stratton engines. If you know your mower brand but not the engine model, you can sometimes find the filter information through the mower manufacturer's website or manual first, then verify it against Briggs and Stratton's chart.

Foam Filters Versus Pleated-Paper Filters

Briggs and Stratton air filters come in two main types: foam and pleated paper. Foam filters (like the 491588) are typically used in smaller residential engines and are washable and reusable. Pleated-paper filters (like the 798897) are used in larger or commercial engines and are usually disposable, though some can be cleaned with compressed air and reused once or twice.

The type of filter your engine uses is determined by the engine design and airflow requirements, not by your preference. You cannot swap a foam filter for a paper filter or vice versa unless the engine is specifically designed to accept both. Using the wrong type can cause airflow problems or allow dirt to bypass the filter.

When you order a replacement, the part number automatically specifies the correct type. If you are unsure whether to buy foam or paper, the filter chart will tell you. Some engines have both a primary filter and an optional secondary or pre-filter for use in very dusty conditions; the chart lists these separately.

What Happens If You Use the Wrong Filter

Using an incorrect air filter can cause several problems. A filter that is too restrictive (smaller or denser than the engine design allows) reduces airflow, causing the engine to run rich and produce black smoke, foul spark plugs, and lose power. A filter that is too loose or has the wrong mounting allows unfiltered air and dirt to enter the carburetor, which can damage the engine over time.

Mismatched filters can also fail to seat properly in the filter housing, leaving gaps where dirt bypasses the filter entirely. This is especially common when using universal or aftermarket filters that do not match the original design. The engine may run at first, but dirt accumulation in the carburetor and cylinder will eventually cause starting problems, rough idle, or loss of compression.

The cost of using the correct filter — usually between $10 and $30 — is far less than the cost of carburetor cleaning or engine repair. Spending a few minutes to verify the part number before purchase prevents these problems entirely.

Frequently Asked Questions

Can I use a universal air filter instead of the Briggs and Stratton part number?

Universal filters sometimes fit, but they often do not seal properly or provide the correct airflow characteristics for your specific engine. Briggs and Stratton engines are engineered with particular filter designs in mind. Using the correct part number ensures proper fit, airflow, and engine performance. The cost difference is minimal, and the risk is not worth it.

Where is the model number located on my Briggs and Stratton engine?

The model and type number is stamped or embossed on a metal plate attached to the engine block, usually on the top or side near the fuel tank or air filter housing. It may also be printed on a sticker. If you cannot find it on the engine itself, check your equipment's manual or the manufacturer's website for your mower or generator model.

Do I need a different filter for winter or dusty conditions?

Briggs and Stratton charts sometimes list optional secondary or pre-filters for use in very dusty environments. These are separate part numbers and are not required for normal use. If you operate your equipment in unusually dusty conditions (like construction sites or unpaved areas), check the chart to see if a pre-filter is recommended for your engine.

Can I wash and reuse a pleated-paper air filter?

Some pleated-paper filters can be gently cleaned with compressed air and reused once or twice, but they are designed as disposable. Foam filters are washable and reusable many times. Check your filter chart or manual to see whether your specific filter is intended to be disposable or reusable. When in doubt, replace it rather than risk reduced airflow.

What if my engine model number is not in the chart?

Very old engines or discontinued models may not appear in online charts. Contact an authorized Briggs and Stratton dealer with your model number, and they can look it up in their complete database or archived manuals. You can also check the equipment manufacturer's manual or contact their customer service for the engine model and filter information.