How to Replace the Cut-Off Knife on an Echo Trimmer (Model SRM-225)

String trimmer out of whack? It's time to face the fix. Whether you are a legendary landscaper or a weekend weed whacker, eReplacementParts.com provides the parts, procedures and facts you need to fearlessly fix what fails you.

The cut-off knife (also known as the cord knife or line cutter) mounts to the shield (guard) on the trimmer. Its purpose is to automatically trim line to the correct length. It's not uncommon for the fasteners that secure the knife to vibrate loose (and disappear). Once the fasteners are gone, the knife is almost certain to follow.

It is important to replace the cut-off knife as soon as you notice that it is missing or damaged. Operating the trimmer without the knife will allow the line to continually "eat away" at the plastic shield assembly. Longer line also increases stress on the engine, which can lead to significant engine damage over time.

This article provides step-by-step instructions for removing and installing the cut-off knife on an Echo SRM-225 trimmer.

Let's get started.

  REMOVING THE CUT-OFF KNIFE [top] 1. Remove the cut-off knife.

Use a wrench or socket to secure the retaining nuts.

Remove the (2) bolts from the top of the shield assembly.

Remove the cut-off knife from the trimmer.

  INSTALLING THE NEW CUT-OFF KNIFE [top] 2. Install the cut-off knife.

Place the new cut-off knife onto the shield and align the mounting holes.

Install the mounting bolts and nuts.

Secure the knife to the shield assembly with the mounting bolts.

You don't have to leverage your savings to level your lawns. As you just learned, repairing your own equipment is easy when you follow our step-by-step guides. Not only did you restore trimmer functionality at a fraction of the cost of replacement; you have taken the edge off of future repairs, wherever you may find them.

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