Air Filter Replacement | Lawn Mower & Small Engine
A dirty air filter starves your engine of air. The result? Hard starting, power loss and increased fuel consumption. Replacing the air filter takes 2 minutes and costs under $15. Here’s how.
Table of Contents
When to Replace
Signs of Dirty Filter
- Hard starting
- Engine running rough
- Black smoke from exhaust
- Loss of power
- Increased fuel use
Replacement Schedule
| Usage | Replace Interval |
|---|---|
| Normal residential | Every season or 25 hours |
| Dusty conditions | Every 10-15 hours |
| Commercial use | Weekly or as needed |
Always check: Before each use. Takes 10 seconds.
[NEED REAL IMAGE: Dirty vs clean air filter]
Filter Types
Paper Element
Most common. Pleated paper in plastic frame.
Pros: Best filtration, no maintenance Cons: Can’t clean, must replace
Foam Pre-Filter
Used with paper filter. Catches large debris first.
Maintenance: Wash with soap and water, let dry, apply light oil.
Foam Only
Found on some older and budget mowers.
Maintenance: Wash, dry, oil lightly.
Dual Element
Paper filter plus foam pre-filter. Best protection.
Service:
- Clean foam every 25 hours
- Replace paper every 100 hours or annually
Replacement by Brand
Briggs & Stratton
Most common engine on residential mowers.
Access:
- Release clips or remove screws on air filter cover
- Pull out old filter
- Clean housing of debris
- Insert new filter
- Replace cover
Filter styles:
- Flat panel (newer engines)
- Cartridge (round or oval)
- Foam (older engines)
[NEED REAL IMAGE: Briggs air filter housing]
Honda
Honda GCV series uses oval cartridge filters.
Access:
- Release cover clips (usually three)
- Remove cover
- Pull filter from housing
- Clean housing
- Install new filter (note direction)
- Replace cover
Tip: Honda filters fit tightly. Make sure filter seats properly.
Kohler
Command and Courage series use panel or canister filters.
Access:
- Remove wing nut or clips
- Remove cover
- Extract filter element
- Separate foam pre-filter if equipped
- Install new elements
- Reassemble
Kawasaki
Common on commercial equipment.
Access: Similar to Kohler - wing nut or clips, cover removal, filter extraction.
Toro
Uses various engines. Check engine brand for specific filter.
Common: Briggs-powered Recyclers use flat panel filter.
Craftsman
Most use Briggs engines. Follow Briggs procedure.
Model-specific: Check under air filter cover for part number.
Cleaning vs Replacing
Paper Filters - Don’t Clean
Paper filters can’t be washed. Attempting to clean them:
- Damages the paper fibers
- Reduces filtration
- May cause engine damage
Always replace paper filters.
Foam Filters - Can Clean
Foam pre-filters and foam-only filters can be washed.
Cleaning procedure:
- Remove foam from frame/paper element
- Wash in warm soapy water
- Squeeze (don’t wring) to remove dirt
- Rinse thoroughly
- Squeeze out excess water
- Let air dry completely
- Apply light coat of clean engine oil
- Squeeze to distribute oil
- Reinstall
Replacement: Even with cleaning, replace foam every 1-2 seasons.
[NEED REAL IMAGE: Cleaning foam air filter]
When Cleaning Won’t Help
Replace filter if:
- Paper element dirty or damaged
- Foam torn or deteriorated
- Filter wet with oil or fuel
- Visible holes or gaps
- Can’t see light through paper (extremely clogged)
Part Numbers
Briggs & Stratton Filters
| Engine Series | Filter Part | Pre-Filter |
|---|---|---|
| 450-550 | 491588S | 271933S |
| 625-725 | 491588S | 271933S |
| 850-875 | 491588S | 271933S |
| Intek Single | 499486S | 273638S |
| Intek V-Twin | 792105 | 792303 |
Honda Filters
| Engine | Filter Part | Notes |
|---|---|---|
| GCV160 | 17211-ZL8-023 | Oval |
| GCV190 | 17211-ZL8-023 | Same as 160 |
| GXV160 | 17211-ZE7-003 | Different style |
Kohler Filters
| Engine | Filter Part | Pre-Filter |
|---|---|---|
| Courage | 20 083 02-S | 20 083 06-S |
| Command | 25 083 01-S | 25 083 04-S |
| 7000 Series | 32 083 03-S | 32 083 05-S |
Toro/MTD Filters
| Model | Filter Part |
|---|---|
| Recycler (Briggs) | 491588S |
| TimeMaster | 119-1909 |
| Craftsman M220 | 491588S |
| Troy-Bilt | 491588S |
Riding Mower Filters
| Brand/Model | Filter Part |
|---|---|
| John Deere S100 | GY20575 |
| Husqvarna YTH | 531 30 73-92 |
| Craftsman T110 | 499486S |
Performance Impact
Dirty Filter Effects
Testing shows dirty filters cause:
- 3-5% power loss (moderately dirty)
- Up to 25% power loss (severely clogged)
- Rich fuel mixture (wastes gas)
- Carbon buildup
Clean Filter Benefits
- Maximum engine power
- Better fuel economy
- Easier starting
- Longer engine life
- Reduced emissions
Common Mistakes
Wrong Filter Size
Using wrong filter leaves gaps where dirt enters.
Always match: Part number or exact dimensions.
Forgetting Pre-Filter
Foam pre-filter extends paper filter life significantly.
Clean pre-filter: Every 25 hours minimum.
Over-Oiling Foam
Too much oil on foam filters restricts airflow.
Correct amount: Filter should be damp, not dripping.
Running Without Filter
Never run engine without air filter, even briefly.
Damage: Dust and debris cause rapid wear to cylinder and rings.
Related Guides
- Lawn Mower Maintenance
- Lawn Mower Won’t Start
- Mower Surging Fix
- Briggs & Stratton Engine Problems
- Honda GCV160/GCV190 Problems
Summary
Air filter replacement is the easiest maintenance task with the biggest impact. A clogged filter causes starting problems and robs power. Check the filter every time you mow. Replace paper filters yearly or more often in dusty conditions. Clean foam pre-filters regularly. Never run without a filter. This simple maintenance extends engine life dramatically.