STIHL FAS55 Trigger Switch Harness FS45 FS55

( Brand: Stihl ), ( Manufacturer Part Number: FAS55 ), ( Model: STIHL FS45 FAS55 ), ( Type: Trigger )

Review STIHL Trigger Switch Harness

The **STIHL FA55, FS45, and FS55 Trigger Switch Harness** represents a precision-engineered assembly designed to elevate the performance, reliability, and user experience of STIHL s mid-size and professional-grade gas-powered chainsaws. This meticulously crafted harness serves as the critical interface between the operator and the engine, ensuring seamless control over throttle response, ease of use, and durability in demanding applications. Built to withstand the rigors of heavy-duty cutting, logging, and professional landscaping, the harness features a robust, ergonomic trigger mechanism that combines smooth, progressive acceleration with a firm, tactile feedback system. The **FA55** and **FS55** models are optimized for larger, high-performance engines, delivering a more aggressive throttle response and enhanced control for extended runtime, while the **FS45** offers a balanced solution for mid-range power needs, ideal for versatility in both residential and light commercial settings. Constructed from high-grade, corrosion-resistant materials, the harness is designed to resist wear, oil, and moisture, ensuring longevity even in harsh environmental conditions. The trigger itself is engineered with a low-friction mechanism to minimize operator fatigue during prolonged use, while the integrated safety features such as the anti-vibration grip and secure mounting enhance both comfort and operational safety. Whether integrated into a STIHL FS55C-B, FS45C-B, or FA55C-B chainsaw, this harness exemplifies STIHL s commitment to innovation, combining cutting-edge engineering with the brand s legendary reliability. For professionals who demand precision, power, and endurance, the Trigger Switch Harness is an indispensable component that elevates the performance of STIHL s most capable chainsaws, ensuring optimal control and efficiency in every cut.

### **Pros and Cons of Buying a Stihl FS45, FS55, or FS55 Trigger Switch Harness**

#### **Overview**

The **Stihl FS45, FS55, and FS55** are popular chainsaws designed for professional and heavy-duty use, particularly in forestry and construction. The **trigger switch harness** (often referred to as the **throttle trigger assembly**) is a critical component that controls engine speed and fuel delivery. Replacing or upgrading it can improve performance, safety, and longevity. Below is a detailed breakdown of the pros and cons of purchasing a new or aftermarket trigger switch harness for these models.

---

### **Pros of Buying a New/Aftermarket Trigger Switch Harness**

1. **Improved Throttle Response**

- A fresh trigger switch harness ensures smoother and more precise throttle control, reducing lag when accelerating or decelerating. This is particularly useful in demanding applications where quick adjustments are necessary.

- Aftermarket harnesses from reputable brands (e.g., **Stihl OEM, Walbro, or other high-quality third-party manufacturers**) often feature improved spring tension and mechanical linkage, enhancing responsiveness.

2. **Enhanced Durability and Longevity**

- Over time, the original trigger switch harness can wear out due to friction, heat, and mechanical stress, leading to stiffness or failure. A new harness eliminates this risk, extending the life of the chainsaw.

- High-quality aftermarket parts are often made from corrosion-resistant materials, reducing wear in harsh conditions (e.g., wet or dusty environments).

3. **Better Safety**

- A malfunctioning trigger switch can lead to sudden engine stalls or unintended throttle engagement, posing safety risks. A new harness reduces the likelihood of such failures.

- Some aftermarket harnesses include **anti-vibration features** or **ergonomic designs**, reducing operator fatigue during prolonged use.

4. **Compatibility with Modifications**

- If you ve modified your chainsaw (e.g., upgraded the carburetor, installed an aftermarket air filter, or adjusted the clutch), a new trigger switch harness can help optimize performance for these changes.

- Some aftermarket harnesses are designed to work seamlessly with **electronic ignition systems** or **digital throttle controls**, offering better tuning flexibility.

5. **Cost-Effective Repair**

- Replacing a worn-out trigger switch harness is significantly cheaper than repairing or replacing the entire carburetor or engine components that may fail due to a failing throttle mechanism.

- Prices for OEM or aftermarket harnesses are relatively low (typically **$20 $60**, depending on the brand and model), making it a practical DIY repair option.

6. **Easier Maintenance**

- A new harness simplifies routine maintenance. Operators can clean and lubricate the throttle mechanism more effectively without worrying about internal wear.

- Some aftermarket harnesses come with **self-lubricating components**, reducing the need for frequent adjustments.

7. **Performance Consistency**

- A failing trigger switch can cause **inconsistent engine RPMs**, leading to poor cutting performance or excessive fuel consumption. A new harness ensures stable operation, improving efficiency and fuel economy.

- For professional users, consistent performance is critical for maintaining productivity and reducing downtime.

8. **Warranty Considerations**

- Purchasing an **OEM Stihl trigger switch harness** (or a high-quality aftermarket part) may void the original manufacturer s warranty if not installed correctly, but it can also extend the lifespan of the chainsaw, potentially saving long-term costs.

- Some aftermarket brands offer warranties, providing peace of mind against premature failure.

---

### **Cons of Buying a New/Aftermarket Trigger Switch Harness**

1. **Potential Compatibility Issues**

- While Stihl s FS45, FS55, and FS55 models share many components, **not all trigger switch harnesses are universally compatible**. Misalignment or incorrect sizing can lead to improper throttle response or mechanical binding.

- Aftermarket parts may not fit perfectly, requiring additional modifications (e.g., filing or adjusting linkages), which could void warranties or complicate installation.

2. **Quality Variability in Aftermarket Parts**

- Not all aftermarket trigger switch harnesses are created equal. **Cheap or low-quality parts** may fail prematurely, leading to repeated replacements and frustration.

- Some third-party brands prioritize cost over durability, using substandard materials that wear out quickly under heavy use.

3. **Installation Complexity**

- Replacing the trigger switch harness requires **disassembling parts of the carburetor and throttle linkage**, which may be challenging for inexperienced DIYers. Improper installation can lead to **leaks, misalignment, or engine damage**.

- If the chainsaw is under warranty, attempting a DIY replacement may void coverage, making professional installation necessary (adding to costs).

4. **Learning Curve for Tuning**

- After replacing the harness, the chainsaw may require **carburetor adjustments** to achieve optimal performance. Operators unfamiliar with tuning may struggle to balance the throttle properly, leading to **poor idling, stalling, or excessive fuel consumption**.

- Consulting a manual or professional tuner may be necessary, adding time and effort.

5. **Risk of Overpaying for OEM Parts**

- Stihl s **official trigger switch harness** is reliable but often **more expensive** than aftermarket alternatives. Unless you prioritize warranty coverage or exact OEM fit, aftermarket options can offer similar performance at a lower cost.

- Counterfeit or knockoff parts may appear cheap but can fail quickly, leading to wasted money.

6. **Potential for Misdiagnosis**

- If the original issue isn t the trigger switch harness (e.g., a faulty carburetor, clogged jets, or a worn piston), replacing just the harness won t solve the problem. Misdiagnosing the root cause can lead to unnecessary expenses.

- Always **inspect other components** (e.g., fuel lines, air filter, spark arrestor) before concluding that the harness is the problem.

7. **Environmental and Operational Factors**

- In **extreme conditions** (e.g., subzero temperatures, high humidity, or dusty environments), even a new harness may wear out faster due to increased mechanical stress.

- Poor maintenance (e.g., neglecting to clean or lubricate the throttle mechanism) can still lead to premature failure, regardless of the harness s quality.

8. **Time and Downtime**

- Replacing the harness requires **removing the chainsaw from service** for installation and tuning. For professional users, this downtime can impact productivity.

- If the chainsaw is part of a fleet, coordinating replacements across multiple units may require scheduling and logistical planning.

---

### **Key Differences Between FS45, FS55, and FS55 Models**

- **FS45**: Smaller displacement (55.5 cc), typically used for lighter forestry work. The trigger switch harness is simpler but still subject to wear.

- **FS55**: Larger displacement (60.2 cc), designed for heavier cutting. The harness must handle higher engine loads, so durability is critical.

- **FS55 (with electronic ignition)**: Some newer models feature **digital throttle controls**, which may require a harness compatible with electronic tuning.

**Note:** Always verify compatibility with your specific model before purchasing.

---

### **Conclusion**

Buying a new or aftermarket **Stihl FS45/FS55 trigger switch harness** is generally a **wise investment** for improving performance, safety, and longevity **provided the right part is chosen and installed correctly**. The benefits of **smoother throttle response, enhanced durability, and cost-effective repairs** outweigh the potential drawbacks for most users, especially those who prioritize reliability in demanding applications.

However, **aftermarket parts carry risks** if not sourced from reputable brands, and **installation errors** can negate the benefits. For professionals or frequent users, **OEM Stihl parts** offer the best balance of quality and warranty support, while **high-quality aftermarket options** provide a cost-effective alternative for DIYers.

If you re considering a replacement, **prioritize compatibility, quality, and proper installation** to ensure the best results.

---

### **Final Recommendation**

- Purchase a **Stihl OEM trigger switch harness** (part number varies by model; check Stihl s official parts catalog).

- Ideal for users who want **guaranteed fit and longevity** and are willing to pay a premium.

- Choose a **high-quality aftermarket harness** from brands like **Walbro, Homelite, or other trusted manufacturers**.

- Ensure the part is **specifically listed for your FS45/FS55 model** to avoid compatibility issues.

- Follow **Stihl s installation guide** carefully or consult a professional if unsure.

- Consider **upgrading to an electronic throttle harness** (if available for your model) for **better tuning control and durability**.

- Pair the harness replacement with a **carburetor tune-up** for optimal performance.

- **Cheap, unknown-brand aftermarket parts** (risk of premature failure).

- **Skipping maintenance** (clean and lubricate the throttle mechanism

Details:

Condition is Used. Shipped with Standard Shipping. Stihl FS45 FS55 Trigger Switch Harness.

part #: fas55 prices

• $5.95-$13.99

specifications strintri:

• brand: Stihl
• mpn: Fas55
• model: Stihl Fs45 Fas55
• type: Trigger

returns strintri:

• paid by: Buyer
• time: 60 Days
• policy: Returns Accepted
• method: Money back

shipping strintri:

• cost: $0.00
• type: Fixed
• class: Standard
• transit: 4-11 Days
• service: Standard

general strintri:

• condition: Used
• Yard, Garden Outdoor Living > Outdoor Power Equipment > String Trimmer Parts

offer strintri:

• options: Ship-to-home
• sold: 0
• availability: In Stock
• started: June 12, 2026
• quantity: 1

seller strintri:

• # reviews: 15208
• city: Sedro Woolley, Washington
• rating: 99.7%

payments strintri:

• credit card: Diners-club
• other
• wallet: Apple-pay

Stihl FAS55 Is Similar To:

• 4110-710-9011b Stihl Brand New Oem Padded Strap Handheld Equipment Harness (33.9% similar) This is a Stihl oem trimmer strap that brand new and has never been used. If you make more than one purchase, I ll be happy to combine the shipping charges for similar items. We no longer cut grass. I kept it as an extra in stock for my weed eaters. Please look at the pictures closely and feel free ...(February 3rd, 2019)
• 4114-430-0200 Stihl Trimmer On Off Stop Switch With Male Connecting End (38.3% similar) And ship in new poly bubble padded shipping mailers for smaller items or boxes larger. Operation and repair service of power tools or equipment is dangerous should only be repaired fixed maintained serviced by those individuals specifically trained to thus said. Stihl on off stop switch, 4 with male...(November 3rd, 2018)
• 4119-710-9011 Stihl Genuine Harness Strap (37.6% similar) Genuine Stihl harness strap part number...(December 14th, 2017)
• 41197109001 Stihl Harness (37.7% similar) Excellent condition...(January 7th, 2018)
• 4126-182-1007 Stihl Trimmer Lever Genuine Nos Oem Throttle Trigger (30.9% similar) Has been in storage for years as such may come dusty and packaging be distressed condition. Stihl 4 trimmer lever genuine nos oem throttle trigger brand: type: lever part: QUANTITY:1 condition: new old stock, sealed generic packaging...(August 11th, 2018)
• 41307106700 Stihl Nos Oem Trimmer Harness Hanger Clamp Collar (41.9% similar) This part does not include the original packaging. Clamp does not include screw. Nos oem Stihl trimmer harness hanger clamp collar includes only the parts that are shown. Please see pictures for best of condition and style. This part may fit many model's. The clamp has fine scratches. The part has ...(September 12th, 2018)
• 41371821001 Stihl Throttle Trigger Oem (39% similar) Stihl throttle trigger FS80 FS85 FC75 1 oem you are buying what is shown in the pictures, item new oem, it works for model's mentioned...(March 18th, 2019)
• 4140-180-1500 Stihl Throttle Trigger Fits Oem Trimmer (37.1% similar) Used Stihl trimmer trigger fits FS38 FS45 FS46 FS55 FS55R...(July 14th, 2018)
• 4147-710-9002 Stihl Full Body Harness (39.5% similar) Selecting the correct return option helps process go faster and smoother. Up for sale is a Stihl full body harness assembly item new without packaging part number: 4 fits model's: most weed trimmer and brush cutter model's - basically, if it has loop to hook to, you can use. Though buyers error is ...(May 20th, 2017)
• 4811-435-0300 Stihl Switch Electric Blower (32.6% similar) Operation and repair service of power tools or equipment is dangerous should only be repaired fixed maintained serviced by those individuals specifically trained to thus said. Compatible with Stihl: SHE71 SHE81 BGE71 BGE81 BGE61 oem part is in stock and ships out fast. And ship in new poly bubble ...(March 23rd, 2018)
• Fs-36 Stihl Used Genuine Trimmer Engine Recoil Switch (43.3% similar) This is a Stihl FS36 engine for parts locked up has everything except carb being sold as thanks looking...(May 3rd, 2018)