Diagnosing AEG Airsoft Gun Issues

02/05/2011 15:25

Everyone experiences problems with their airsoft gun sometime; after all, it's a machine, and machines break down. But how do you tell what is wrong, and how to fix it? Well, although it isn't really possible to tell exactly what the problem is without disassembling the weapon, it is possible to make an accurate guess.

In this article, I be examining problems and their possible causes, as well as solutions to those problems.

Please remember, however, any work on your airsoft gun should be done by a professional, or someone who has had significant experience with airsoft gun repair. Any tampering you choose to do with your airsoft gun is completely at your own risk.


Symptoms may include:

1. Gun sounds like it is shooting but no bbs are coming out the barrel

2. Gun is not shooting at all; motor may be making a whining noise when trigger is pulled

3. Fuse is repeatedly blown

Possible Causes:

1. Low quality bbs. Any low quality bbs (bbs with air bubbles, seams, or other defects) will cause jamming and damage to your airsoft gun.

2. You have the hop-up turned up to much. If such is the case, the nub that gives the bb it's backspin could actually be preventing the bb from being blown out the barrel. 

3. The shims in your gearbox are defective. Shims are basically little washers that are used to space gears properly between the two side pieces of the gearbox shell. If the shims are defective, it could be cause the gears to wobble so much that they "lock up"; thus causing the gearbox to jam.


1. Use high grade bbs

2. Make sure the hop-up is adjusted properly

3. Have your gearbox re-shimmed



Symptoms may include:

1. Gun does not shoot when trigger is pulled

2. Gun does not shoot every time the trigger is pulled

Possible Causes:

1. Broken trigger post. There is a small metal post located directly behind the trigger assembly; this post prevents the top of the trigger assembly from going to far back and hitting the gears. When this post breaks, a cut-off lever is engaged, preventing the trigger assembly from completing the electrical circuit which fires the gun.

2. Bad wiring. It could be that the wiring in your airsoft gun is defective, thus when the trigger is pulled, there is no electical current generated to fire the gun.

3. Blown fuse. When the fuse is blown, electricity is prevented from flowing from the battery and through the wiring. Therefore, when the trigger is pulled, no electriciy is generated to fire the gun. 


1. Buy a new gearbox shell, whole new gearbox, or whole new gun - or replace the trigger post. (For instructions on replacing a broken trigger post, see "Replacing a Broken Trigger Post")

2. Replace wiring. This will be an in-depth job that requires expertise.

3. Replace the fuse. Most airsoft retailers will probably have spare fuses available for sale. Walmart also sells fuses - just be sure to get the right type (see your airsoft gun manual for details).



Symptoms may include:

1. Drastically reduced range

2. Less power

Possible Causes:

1. Rotten O-ring. The O-ring goes on the piston head and creates the airseal necessary for compression.

2. Stripped piston. The teeth on the piston have been worn off, thus preventing the piston from completing it's cycle.

3. Worn out spring. Over time the spring in your airsoft gun will lose its "stretchiness", resulting in reduced FPS.

4. Defective air nozzle. The air nozzle is a part of the gun that compressed air flows through to propel the bb forward.


1. Replace O-ring

2. Replace Piston

3. Replace spring

4. Replace air nozzle



Symptoms may include:

1. Less accuracy

2. A wider-than-usual spread on full auto fire

Possible Causes:

1. Dirty barrel. Dirt in the barrel will knock the bb around, thus causing it's flight path to be irregular and inaccurate

2. BBs. Light wieght bbs, such as .12g, or .15g bbs, will GREATLY reduce the accuracy of your gun, and can also cause gun damage or even failure.


1. Clean your barrel. This should be done at least every few games. If you have been playing in dry, dusty conditions, or other dirty environments, you should clean your barrel after every game day.

2. Use heavier weight bbs. Definitely do not use any bbs lighter than .20g. (you probably don't want to go any heavier than .28g unless you are sure that your gun can handle it.)



Symptoms may include:

1. Gearbox is making complete cycles but not bbs are being shot.

Possible Causes:

1. Need to wind magazine more (if high-cap)

2. Jamming

3. Magazine feeding issues

4. Defective Tappet Plate


1. Wind magazine using the wheel on the bottom of the magazine (or use quick wind if compatible)

2. Unjam barrel using the cleaning/unjamming rod that came with the gun. Remove magazine and battery, then, using the wedge-shaped end of the rod, start at the end of the barrel and push rod toward gearbox. Repeat until all jammed bbs are removed

3. Test magazine in another compatible gun. If magazine still does not function properly, do not use.

4. Remove gearbox from gun and make sure air nozzle is moving back and forth when gun cycles. If it is not, then tappet plate or sector gear may be broken or defective.


Article by Striker




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