JG / CYMA 8mm Reinforced Gearbox for M4 M16 Series Airsoft AEG with Mosfet - Rear Wired

$70.00 $59.50

Model: GB-M4-MOS8mm-B

10 Customer Reviews

by Kenneth L. on 08/18/2014
"I got this about 2 weeks now, and had to wait to my upcoming event to have a true test. I was able to hit targets at least 50+ft with confirm hits, debatable around 80ft. Mine came with a ported cylinder shooting at 348fps, which it isnt that bad. However, if you want full power change it to a non-ported cylinder.

MOSFET is COMPLETELY different from the picture and its an APS MOSFET. Since its rear wired, you have to either use a stick battery or use a nun chuck for crane style stocks.

All in all, it performs really good, and I am satisfied with my purchase :D
by Steve J. on 08/06/2014
"I bought this gearbox to replace an old gearbox that had issues.
Taking it out of the box everything looked in order. I dropped it into my KA OA-15 M8 and tested the weapon. The first 10 shots seemed decent, that's where it goes bad. After about the 10th round bb's started flying everywhere, dropping, rising, no consistency whatsoever. 50 Ft shot group was about 15 feet wide. So I checked out my barrel / hopup to see if there was something wrong with the gun, nothing found. So I decided to look further into the new gearbox... I opened it up.

There was rust on the gearbox housing internally.... yup....
Bushings not Bearings
There was enough grease to drown the fonz (old reference?!)
The cylinder had almost no air seal / compression
The Air nozzle and piston had the quality of a cheap model car set.
Horrible Shimming
The spring had no... spring...

So I paid to basically get a set of spare parts, which I was able to use to create a decent gearbox when I cleaned it up, reshimmed, put in a new spring, piston, air nozzle and properly sealed the cylinder.

I gave it a two for two reasons -
First, at least all the parts were there?
Second, the wiring harness and mosfet were in excellent condition.
by Neal R. on 06/02/2014
"Just got mine today it looks different from the picture and has a aps MOSFET (decent) but only thing I'm having problems with is getting the motor to fit into it I think the MOSFET wiring and soldering is getting in the way of the motor gear and I can't get the cap on to suck the motor up in there but everything else seems fine haven't got to shoot due to motor not being able to fit good or something I got the G&P 120 motor might have been worth to have just gotten a whole new pro kit receiver motor gearbox and all for 120

JG / CYMA 8mm Reinforced Gearbox for M4 M16 Series Airsoft AEG with Mosfet - Rear Wired
The JG Mosfet Enhanced 8mm Gearbox is a high performance and high quality release from JG / CYMA which has been proven by their release in the popular rifles. Need to replace your gearbox or just looking for something new to upgrade your old AEG? Look no further than the JG 8mm Gearbox.

- Velocity output for this gearbox is estimated to 370~460 fps.
- Wiring to the back. Includes High Performance Mosfet Unit.
- 8mm Metal Bearings.
- Ball bearing metal spring guide.
- Reinforced Piston / Piston Head.
- Reinforced JG Gear set.
- Reinforced Cylinder and Cylinder Head.
- Low Resistance wiring harness set. (May come in clear or black/red wiring wrap.)
- Reinforced Mech Box Shell.

Complete Gearbox Disclaimer:
We have compiled a series of videos for AEG take down, assembly and gearbox for your reference. Recommended for experienced players only. A "gearbox" virtually never breaks, Evike.com offers spare parts for all components. All gearboxes are sold as complete set of parts and "AS IS". All the gearbox are directly from manufacture. Buyer responsible for fine tuning and proper installation. Evike.com is not responsible for shimming it perfectly or playing the game of airsoft for you.
For more information on complete gearboxes, please visit: Complete AEG Gearbox

About JG / ASP

JG / Jing Gong (China) / ASP (Hong Kong) is among the world's largest Airsoft OEM (Original Equipment Manufacturer) and pioneer for high quality Airsoft AEG rifles. With superb production capability, volume, and their close relationship Evike.com positioned JG to provide the world market with great reliable products.

Wanna chat about JG / CYMA 8mm Reinforced Gearbox for M4 M16 Series Airsoft AEG with Mosfet - Rear Wired?

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