How To Replace the Starter on a Gas Trimmer

Many 2-cycle trimmer models share similar designs, even between different manufacturers, so the steps for many trimmer repairs are often similar between trimmers.

Likewise, the steps for replacing a 2-cycle trimmer starter assembly are very similar for hundreds of trimmer models, and starter replacements are a very common type of tool repair.

This article covers the general steps to replace a trimmer starter in most 2-cycle trimmers. We use the Shindaiwa T-231 trimmer as our demonstration example.

How Trimmer Starter Assemblies Work

Like the starters of most 2-cycle engines, a trimmer's starter assembly uses several parts to do its job.

Starter assemblies consist of a pulley, a starter pull cord, a return spring that rewinds the cord, and a clutch-like system that engages the engine crankshaft.

• Pulling on the starter cord rotates the starter assembly. Because the starter assembly is engaged in the crankshaft, pulling the starter cord also turns the engine crankshaft.

• Turning the crankshaft causes the engine's flywheel to turn. The flywheel passes magnets as it turns that help it to generate electrical energy.

• Electrical energy from the turning flywheel is transferred to the engine's ignition coil. Electricity then passes from the ignition coil to the spark plug, ignites the engine's fuel, and starts the machine.

In short, your trimmer's 2-cycle engine needs a little human power to help it generate a spark that will start its engine, and the starter assembly is responsible for the first step in converting human power to engine power. It's not hard to see why having a properly working starter is important. 

Any part of a starter breaking or becoming damaged usually requires replacing the starter. The most common reason for replacing a starter assembly is the pull cord breaking. Individual parts of a starter can be replaced, but the truth is that the small amount of money you usually save on parts isn't enough to justify the difficult  task of rebuilding the assembly.

Starter assemblies usually cost little more than their individual parts, and considering how easy they are to replace, replacing the entire assembly is usually the best choice when just one of its parts fails.

Trimmer Starter Replacement Steps

Of course, these steps may be just a little different for different trimmer models, but the general idea is the same:

• Remove screws and other parts that hold the starter assembly in place.
• Remove the old assembly.
• Install the new assembly.
• Engage the starter in the crankshaft.
  
• Affix the new assembly by replacing screws and other parts that hold it in place.

 We use the Shindaiwa T-231 in our demonstration, but its repair steps will be very similar to those of most trimmers.

Step 1 Unscrew the Four Screws Holding the Starter Assembly in Place

• For the T-231, these are the only fasteners holding the assembly down. Unscrew them with a hex driver. Use an appropriate driver for other trimmer models.