Maintaining the Fusion Engine A&K Masada

To lubricate or remove the nozzle from the Fusion Engine powered A&K Masada, the Fusion Engine does not need to be removed. The upper cylinder assembly only needs to be loosened so it can be rotated up and the front cylinder can be removed.


  1. Remove the upper receiver.
  2. Remove the rear  Fusion Engine bolt.
  3. Remove the stock.
  4. Detach the nozzle banjo connector
  5. IMG_0462Remove the front mount screw.
  6. IMG_0463Gently rotate the upper cylinder up.
  7. UIMG_0464nscrew the front cylinder. If the top spacer gets in the way, it can be removed.
  8. Lubricate the nozzle following the instructions here.
  9. When reassembling the gun, follow the nozzle alignment instructions below.

To remove the Fusion Engine from the lower receiver:

  1. Remove the upper receiver.
  2. Remove the rear bolt.
  3. Remove the stock.
  4. Remove the motor plate (w/grip connect, if installed).
  5. Remove the grip screws
  6. IMG_0461Remove the mag release assembly
    1. Pull down the bolt release lever
    2. While holding down bolt release lever, push in the mag release from the left side
    3. Unscrew the mag release button on the right side
  7. Fusion Engine should pull straight out.

To reinstall the Fusion Engine:

  1. Basically Reverse the steps above.
  2. Put the fire select switch into Semi position, so it will line up with the selector plate
  3. Align the nozzle per instructions below.


When assembling the Fusion Engine into the lower receiver, the nozzle will not be aligned properly. The nozzle alignment is controlled by the screw at the back of the Fusion Engine. First lightly tighten the grip screws on the Fusion Engine. You notice that the nozzle rests firmly on the nozzle guide. The rear Fusion Engine screw should then be tightened down gently while watching the nozzle and you will see the nozzle slowly elevate and become parallel to the nozzle guide, just barely floating above the guide. This can be verified by pressing down on the top side of the nozzle and you’ll be able to observe it depress so you know it’s not resting directly on the guide. Do not over tighten the rear screw. IMG_0148Once the nozzle lifts off the guide and is parallel to the guide, do not tighten any further.

Verify that the nozzle is centered in the hopup and the bucking lip is not pinched. Using a flashlight, look down the end of the barrel (make sure the air is disconnected, safety

Nozzle catching bucking lips. When the gun is closed, the nozzle will catch the bucking lips. Dry fire the gun a few times to properly seat the nozzle in the bucking.

Nozzle catching bucking lips. When the gun is closed, the nozzle will catch the bucking lips. Dry fire the gun a few times to properly seat the nozzle in the bucking.

first!) If the bucking lip is pinched, dry fired the gun several times to try and get the bucking to seat the nozzle cleanly. Alternatively, loosen the barrel assembly and extract it slightly, then re-seat it. This will slide the bucking straight over the nozzle.

Nozzle properly seated.

Nozzle properly seated.

The pictures to the right show a nozzle with the bucking lips pinched, and one that is properly seated (it’s from another gun, but it depicts the same issue).

IMG_0459The wire harness should be routed along the side of the BB feed guide and under the upper receiver. The hopup block has been modified to make room for the wire harness. This allows the wire harness to run to the front hand guard easily without interfering with the bolt cover.

I like the A&K Masada Fusion Engine gun so much I am now selling pre-converted Fusion Engine A&K Masada airsoft guns. Contact me for more information.

Happy Airsofting!

– Rudy