Kobalt KST 4040X-06 - User Manual

Questions and Answers

A
Adrienne SmithAug 7, 2025
Why does my Kobalt KST 4040X-06 motor fail to start?
- J
  Jane LongAug 8, 2025
  If the Kobalt Trimmer motor doesn't start when you press the switch trigger, there could be a few reasons. First, check that the battery is securely in place, ensuring the latches on the battery compartment snap into place. Another possibility is that the battery isn't charged, so charge it following the instructions that came with your model. If these steps don't work, there might be a wiring or electrical contact issue, so call 1-888-3KOBALT (1-888-356-2258) for technical service.
C
Courtney AndersonAug 17, 2025
What to do if Kobalt Trimmer head will not advance line?
- J
  Joshua DixonAug 17, 2025
  If the Kobalt Trimmer head won't advance the line, it could be due to several reasons. First, stop the trimmer, remove the battery, and check if the motor shaft or trimmer head is bound with grass, and remove any grass. Also, the spool may not have enough line, so remove the battery and replace the trimmer line. In addition, a dirty trimmer head could be the culprit, so remove the battery and clean the spool. Lastly, the line might be tangled on the spool; in this case, remove the battery, take the line off the spool, and rewind it.
A
Allen GilmoreAug 26, 2025
How to fix Kobalt KST 4040X-06 line not cutting well?
- L
  Larry FrancisAug 26, 2025
  If the line on your Kobalt Trimmer isn't cutting well, it could be that the cutting blade on the guard has become dull. You can sharpen the cutting blade with a file or replace it with a new blade.

Summary

Product Specifications

Package Contents

Hardware Contents

Symbols

Safety Information

Child Safety

Safety guidelines for children's interaction with the trimmer.

Assembly Instructions

Guard

Instructions for attaching the protective guard to the trimmer head.

Connect upper;lower trimmer tubes

Steps to join the upper and lower sections of the trimmer shaft.

Front handle

Procedure for attaching and positioning the auxiliary front handle.

To remove the cutting line

Guide on how to disassemble the spool to remove old cutting line.

To Install the cutting line

Steps for installing new cutting line onto the spool.

To replace the bump knob

Instructions for removing and replacing the bump knob on the trimmer head.

Battery

Procedures for installing and removing the battery pack.

Adjusting the cutter blade

Guidance on adjusting the line cut-off blade for different cutting swath sizes.

Operating Instructions

Turn on;off

How to start and stop the string trimmer using the trigger and lock-off lever.

Lengthening the line

Explanation of the bump feed mechanism for advancing cutting line.

Trimmer tips

Practical advice for effective and safe use, including pre-use and during-use tips.

Care and Maintenance

Trimmer Guard and Motor Maintenance

Steps for cleaning and maintaining the trimmer guard and motor area.

Troubleshooting

Warranty

5-YEAR LIMITED WARRANTY

Details of the limited warranty coverage, duration, and conditions.

Replacement Parts List

Kobalt KST 4040X-06 Specifications

General

Type	String Trimmer
Voltage	40V
Battery Type	Lithium-Ion
Runtime	45 minutes
Line Feed	Automatic
Attachment Capable	No
Battery Included	Yes
Charger Included	Yes
Cutting Width	13-in
Line Diameter	0.080 inches
Cutting Path	13-in