Zius BK2S Mod Guide: CQB Kits, Stocks & Magazines

Monkee Mods

Zius BK2S Mod Guide: CQB Kits, Stocks & Magazines

The Zius BK2S is the compact PDW member of the BK1S/BK2S automatic electric blaster family. It shares the receiver, gearbox and electronics with the longer BK1S but uses a shorter barrel, handguard and retractable stock. Its most useful mods change the overall format, battery space and proprietary magazine handling.

Stock performance / design: Monkee Mods' first look reports roughly 160 FPS for the shorter BK2S. The platform uses an XT-30 battery, T238 control electronics and a shared mechanical system with the BK1S.

Available Monkee Mods parts for this platform

PartWhy you'd want it
MM BK2S CQB KitCreates the shortest MP5K-style configuration and moves a buffer-tube-size battery into the top compartment.
MM BK2S Honeybadger 4.5 Inch HandguardChanges the short front end while retaining a conventional handguard and top rail.
Zius BK2S Retractable ButtstockRestores or replaces the original compact PDW stock.
MM BK2S Buttstock ExtensionLengthens the PDW layout and creates room for a standard buffer-tube-size battery.
Zius BK1S Buffer Tube and Buttstock ComboConverts the BK2S rear end to a standard AEG-style stock.
GE Power 1200mAh 40C BK2S BatteryFits the stock BK2S battery compartment without changing the rear furniture.
Zius BK1S/BK2S MagazineAdds a proprietary 12-round spare; the listing notes room for about 13-14 stiff-foam darts after removing its limiter.
MM BK1S Stanag Mag SleevesExtend the shared BK1/BK1S/BK2S magazine format to 15 rounds.
MM BK1S Magwell Flare 2.0Enlarges the reload opening for either standard or sleeved magazines.
Microswitch SetReplaces the gearbox switch and wiring.
Dart GateReplaces the gate and breech return spring when feeding parts are worn or damaged.
Zius BK1S/BK2S MOSFET (T238)Restores the platform's control electronics; the store lists it as a replacement, not a higher-spec board.
Short Shaft 480 MotorReplaces the matching gearbox motor.
Plunger Tube and Rod AssemblyReplaces the shared air-compression assembly.
Gearbox with Motor CageReplaces the complete mechanical drive housing, trigger and motor cage.
Receiver ShellReplaces the shared outer receiver without changing the BK2S front or stock format.

Recommended mods & why

  • Choose the body and battery layout together. The CQB top compartment, extended PDW stock and AEG buffer-tube conversion solve battery space in different ways.
  • Build capacity around the proprietary magazine. The sleeve and magwell flare improve the existing BK magazine rather than converting the receiver to Talons.
  • Treat electronics and gearbox products as service parts. The current product pages do not claim that the MOSFET, motor, dart gate or gearbox alone raises output or rate of fire.

Sources

Other platform mod guides

ZWQ S400, ZWQ S100, Worker Harrier, Monkee Mods Firefly, Worker Seagull, Hare Diana and AIT Lightning.