Troubleshooting Selector Switch/Optical Sensor Issues

MTWs manufactured after October 1, 2021 are equipped with the black Spartan Electronics board with an optical select-fire sensor. This sensor works by detecting a dark or light surface on the selector barrel. Detecting a light surface will set the MTW to semi-auto and detecting a dark surface will set the MTW to full-auto.

A sticker or paint can be used to ensure that the two surfaces are detected correctly by the sensor.

Spartan Electronics for MTW-Spec Fire Modes

MTW Fire Mode Select Demonstration. See the instructions below for AEGs.

The Spartan Electronics board can be cycled through several different fire modes as listed below. To advance to the next fire mode, set your gun to semi mode and hold the trigger. After 5 seconds (MTW version) or 10 seconds (AEG Version), the board will advance to the next setting.

MTW (Hold 5 seconds to change modes)
• Semi / Full Auto (Default in US)
• Semi / 3-Round Burst
• Semi / 2-Round Burst
• Semi / Semi (Default in UK)
• 2-Round Burst / Full Auto

AEG (Hold 10 seconds to change modes)
• Semi / Full Auto (Default in US)
• Semi / 3-Round Burst
• Semi / Semi (Default in UK)


*Boards sold in Germany are locked in
Semi / Semi mode.

Empty Mag Detection Traditional and Simplified Modes

The Spartan Electronics for MTW board will automatically disable firing after the last BB is fired when using a Wolverine Airsoft MTW Magazine. Firing will resume in one of two ways depending on the following settings:

• Traditional (Default): To reset empty mag detection, the user must press the Bolt Catch after loading a new magazine.

• Simplified: The MTW will automatically reset empty mag detection when the magazine is removed without requiring use of the Bolt Catch. We recommend putting the MTW in simplified mode when using standard AEG magazines that do not have empty mag detection.


To change between Traditional and Simplified mode simply place the selector on semi and hold down the trigger and the bolt catch for 5 seconds.

Spartan Electronics for MTW-Spec Optical Sensor Cleaning

If the optical select-fire sensor on the MTW Spartan Electronics Control Board is giving inconsistent results, it may be necessary to clean the contacts on the board. After removing the electronics from your MTW, remove the electrical tape from the back of the board to reveal the sensor contacts. Clean them thoroughly with 70% or better isopropyl alcohol. After allowing the contacts to dry, re-apply the electrical tape and reinstall the board in your MTW.

For instructions on removing/installing the control board, see this video.