ADZZZYs Armoury show how they upgraded a Tokyo Marui MP5K AEG to have a higher rate of fire. This AEG arrived at the workbench sounding quite unpleasant. Upon opening the gearbox, it becomes evident that a previous technician left behind some questionable work. The original setup suffered from an incorrectly spaced piston that was actively colliding with the gears, a classic case of internet-acquired knowledge meeting a lack of real-world common sense.

To rectify the situation while respecting the owner's budget, several targeted upgrades are installed. The plastic bushings are replaced with sturdy metal ones, a new piston is fitted to eliminate compatibility issues, and the existing gears are short-stroked by four teeth to decrease required volume. A reliable Perun MOSFET replaces the old unit to bring some intelligence to the trigger response, and a sector chip is added to ensure smooth feeding during rapid cycles.

Testing reveals a dramatic improvement in audio quality and performance, transforming the rough-looking airsoft gun into a functional sleeper. With the stock motor and an 11.1-volt battery, the build comfortably achieves 20 rounds per second. Swapping in a 35,000 RPM upgrade motor pushes that number to a blazing 25 rounds per second, which the gun tech notes is more than enough unless you specifically enjoy being unfriendly to other players on the field.