Airsoft Systems ASCU Fire Control System for Ver 2 AEG Gearbox - Gen 4

Airsoft Systems42081
3.7 stars, based on 12 reviews


ID: 42081 (Burst-ASCU-V2G4)
The manufacturer of this product enforces a strict minimum advertised price (MAP) policy which excludes this product from any additional discount coupon codes. This item, however, may qualify for free shipping.

12 Customer Reviews

by Justin R. on 05/09/2016
"After having a terrible experience with Gen1 and Gen2, I figured I would give this new Gen4 a try.

I just got it in the mail today. The installation was not great. The fit was VERY tight. After a little sanding on the large plastic cover, I got it to fit snug. I wired it all up being careful not to strip or pinch anything, plugged a 7.4 in and it fired fine three times. Then I could smell smoke and it started firing on auto by itself.

I took it out and observed that one of the mosfet had burned. Save yourself the $100 and find something else.

This is probably the worst airsoft investment I've ever had.
by Morgan S. on 11/01/2015
"My personal experience with this product was rather poor. The connectors between the two control boards broke quite soon, so I'm afraid I can't recommend this product. It's extremely poorly designed, for the price, there are many better options.

Pros of any simple mosfet system:
-Protects your trigger contacts and electrical system

Pros over simple mosfet systems:
-Marginally reduces trigger pull force
-Ensures a full piston cycle (improves trigger response and mechanical longevity)
-Three round burst if you want it
-No soldering required

-EXTREMELY fragile connectors are prone to breaking at the slightest touch
-Uses extremely stiff wire instead of wet noodle wire, making the install a pain
-Poor electrical design, many users say it burns itself out extremely soon

Really, the only core advantage of this mosfet over cheaper and simpler systems is that it gives you full piston cycles. The reduction in trigger pull isn't very perceptible, three round burst is really just a gimmick, and any good airsoft tech should be comfortable soldering.

Furthermore, the warranty service is seemingly nonexistent, as I have emailed them twice about my problems to no avail.

So, I'd advise you to stay away from this product. If you want a mosfet that gives you full piston cycles, I'd recommend one of the mosfets made by Black Talon (not offered on They have superior construction, better warranty, and are simply a better product for almost the same price. They might 10 or 20 dollars more than the ASCU, but it's well worth it.

If full piston cycle isn't important to you, then learn to solder and make your own darn mosfet. It quite literally costs 10 dollars to make one.

The point is, stay away from this POS.
by Chas G. on 09/12/2015
"I just finished installing the ASCU-2 Gen 4 into my heavily modified, Lonex based gun. The install was completely smooth and trouble free. Others here have said that they had to modify the unit to get it to fit into the shell, I did not experience any of that at all. The unit slide right into my Lonex gearbox perfectly! Everything fit like it was made to fit into my gearbox shell. The only modification I made was changing out the small Tamiya battery connector to a Deans connector. Super simple for me.

I have a Lonex A1 motor in this gun and figured that would be considered an up graded motor so I left the anti-reversal latch out of my built and it worked perfectly.

I also had a SPEED trigger already in this gun and so with some minor tuning of the trigger throw I had it set to have an incredibility fast and very slight trigger pull to fire a shot. This system was made to take advantage of the SPEED triggers.

I simply followed all the instructions in the well thought out, English manual that comes with color pictures as well. So often in airsoft we buy stuff that has either useless or non-existent instructions. This fire control unit kit has a very well written (actually a couple typos, but who's counting) and easy to understand manual! Such a relief as there are a couple of things that if you install this wrong you can destroy your unit.

After it was in and the gun put back together I test fired it quite a bit and it worked flawlessly! In a week I will be using this gun at a large MILSIM event and hope to see the full nature of this system in action.

-Easy to install
-Instantaneous trigger response!
-Well thought out system
-3 round burst FTW!
-Detailed manual

-Needs to have an up-rated motor to work properly and as designed
-Delay between trigger pulls in semi and 3rd burst mode (probably a designed in feature, but I wish it had less delay between pulls. I am nit-picking here.)
Airsoft Systems ASCU Fire Control System for Ver 2 AEG Gearbox - Gen 4
Airsoft Systems ASCU Fire Control System for Ver 2 AEG Gearbox - Gen 4


  • Ultra fast trigger response
  • Optional Bolt-Stop simulation
  • New MosFet transistors with 16 times less resistance, resulting in to faster cycle, better active brake, more shots per battery charge and less heat
  • Simple drop-in installation
  • No soldering required
  • Improves gearbox reliability
  • Updated software with easier programming (accidental hop-up program activation is impossible).
  • Improved selector plate
  • Fits all standard and reinforced version 2 gearboxes
  • Better short-circuit protection
  • 3 year world wide warranty offered from Airsoft Systems
  • Compatible with LiPo, LiFe, NiMH, and NiCd batteries from 7.2V to 12V

Package includes: FCU, Selector plate, Cut-off lever
Compatibility: For most standard Version 2 AEG Gearbox

Manufacturer: Airsoft Systems

Wanna chat about Airsoft Systems ASCU Fire Control System for Ver 2 AEG Gearbox - Gen 4?

Have questions about this item? We monitor these comments daily, but it may be faster to email us directly or call us at 1-626-286-0360.

Facebook about THIS with your friends! Comment for a chance to win awesome airsoft prizes. Details can be found on The Evike Facebook Fan Page HERE! Remember to leave "Also post on Facebook" checked to qualify your comment!

Items on Sale