SRM-225 String Trimmer Head - Fits Echo SRM-225, SRM-210, SRM-2100, SRM-200 | 2 Pack

SRM-225 String Trimmer Head

Key Features

• 30-Second "Easy-Load" Technology: The patented Speed-Feed 400 design allows you to reload the entire head with trimmer line in under 30 seconds without disassembling the housing or removing the spool.
• High-Capacity Dual-Line Spool: Specifically engineered to hold up to 20 feet of 0.095" diameter line, providing extended run times for both residential landscaping and heavy-duty brush clearing.
• Precision Bump-Feed Advancement: Features a balanced internal mechanism that ensures reliable line advancement with a light tap on the ground, minimizing line welding and jams even at high RPMs.
• Impact-Resistant Structural Polymer: Manufactured from specialized glass-reinforced nylon to withstand high-velocity contact with rocks, curbs, and fence posts while maintaining structural integrity.
• Low-Vibration Balanced Design: Centrifugally balanced to reduce engine and shaft vibration, leading to less operator hand fatigue and a longer lifespan for your trimmer's gear head bearings.

Replaces / Cross-Reference Part Numbers

• Echo Speed Feed 400: 99944200907, 99944200907B, 99944200902, 99944200900

Compatibility & Fitment

This "400" series head is the standard professional choice for Echo and Shindaiwa straight-shaft trimmers. Key compatible models include:

• Echo SRM Series: SRM-225, SRM-225i, SRM-210, SRM-2100, SRM-200, SRM-230, SRM-250, SRM-265, SRM-266.
• Echo PAS Series: PAS-210, PAS-211, PAS-225, PAS-230, PAS-265, PAS-266.
• Shindaiwa T-Series: T195S, T220, T222, T230, T231, T242, T242X.
• Technical Specification: Fits all straight-shaft models utilizing the M10 x 1.25 LHF (Left Hand Female) arbor thread.

When to Replace

• Worn-Through Bump Surface: The center knob has ground down from pavement contact to the point where the internal spring is visible or the line no longer advances correctly.
• Cracked Outer Shell: Visible stress fractures or missing chunks in the black housing which can cause the head to shatter or become dangerously unbalanced at high RPMs.
• Loading Mechanism Failure: The internal eyelets no longer align with the loading arrows, or the twisting mechanism has become seized with dried sap and dirt.
• Metal Eyelet Damage: The line exits are missing or have developed deep grooves, causing the trimmer line to snap off inside the head repeatedly.
• Excessive Vibration: The head is no longer balanced due to uneven wear, putting undue stress on the gear head and the trimmer's motor.

Installation Tips

• Left-Hand Threads: Remember, this head is Left-Hand Threaded. To tighten it onto the trimmer, you must turn the head Counter-Clockwise.
• Lock the Gear Head: Insert a small hex key or the factory locking pin into the gear head hole to hold the shaft stationary while you spin the old head off and the new one on.
• The Loading Arrow: To reload, rotate the top knob until the arrows on the knob align perfectly with the metal eyelets. Push your line through the head until it is even on both sides, then twist the knob to wind.
• Optimized Line Diameter: For the SRM-225, 0.095" line provides the best balance of durability and cutting power without over-stressing the engine.
• Soak Your Line: To extend the life of your trimmer line, soak it in water for 24 hours. Hydrated nylon is much more flexible and significantly less likely to snap at the eyelet during heavy use.