Air Fuel Filter for Stihl FS38 FS45 FS46 FS55 KM55 – 10 Pack

Replacement Air Fuel Filter for Stihl String Trimmers

Keep your Stihl trimmer running at peak performance with this direct-fit replacement air fuel filter (OEM reference: 4140 124 2800). Designed specifically for Stihl FS and KM series string trimmers, this foam filter ensures your engine receives clean, consistent airflow and fuel delivery — helping maintain smooth operation and extend engine life.

Compatible Models

• Stihl FS38
• Stihl FS45
• Stihl FS46
• Stihl FS55
• Stihl FS55R
• Stihl KM55

Product Details

• OEM Part Reference: 4140 124 2800
• Material: High-quality foam construction
• Size: 6.8 cm
• Fit: Direct drop-in replacement — no modification needed
• Quantity: 10 pieces per pack

Why Replace Your Air Fuel Filter?

A clogged or worn air fuel filter can cause your Stihl trimmer to run rough, lose power, or fail to start. Regular replacement is one of the simplest and most cost-effective ways to maintain your outdoor power equipment. This 10-pack ensures you always have a spare on hand for the season ahead, so your trimmer stays ready whenever you need it.

Key Benefits

• ✅ Exact-fit replacement for listed Stihl models — installs in minutes
• ✅ Foam construction traps debris and contaminants effectively
• ✅ Helps maintain consistent engine performance and fuel efficiency
• ✅ Affordable 10-pack value — great for seasonal maintenance
• ✅ Works right out of the box — no tools or special skills required

For guidance on small engine maintenance best practices, visit the U.S. EPA Small Engine information page.

Frequently Asked Questions

Q: Which Stihl trimmer models is this air fuel filter compatible with?

A: This replacement air fuel filter (part reference 4140 124 2800) is compatible with the Stihl FS38, FS45, FS46, FS55, FS55R, and KM55 string trimmers. It is a direct drop-in fit requiring no modification.

Q: What is this air fuel filter made of, and what size is it?

A: The filter is crafted from durable foam material and measures 6.8 cm. The foam construction effectively captures dirt and debris to protect your engine's carburetor and fuel system.

Q: How many filters are included in one order?

A: Each order includes 10 replacement air fuel filters, giving you excellent value and ensuring you have backups ready for future maintenance needs throughout the trimming season.

Q: How often should I replace the air fuel filter on my Stihl trimmer?

A: It is generally recommended to inspect and replace your air fuel filter at the start of each season or more frequently if you use your trimmer in dusty or demanding conditions. Regular replacement helps maintain smooth engine operation and optimal fuel flow.