AOSC Forum Archive

I was adjusting the motor height in my G&P M16a3 today because it sounded a little off. After doing an adjustment, I went outside to test fire. After firing a few shots in both semi and full, the gun ceased to function. My first thoughts were that maybe the motor was too high, or maybe a wire burned out.

Fast forward about half an hour, and my rifle is disassembled. I connect the battery and touch the trigger contacts together to see if the motor will turn, and I get nothing except for a little smoke from the contacts. Out of curiosity I hooked up another motor and found that it worked perfectly fine. Upon further examination, I found that the misbehaving motor's pinion gear will not rotate when turned by hand. Without much forethought, I got some pliers and forcefully turned the pinion gear, making it possible to turn by hand again. (Although it has a rather grainy sound to the rotation.)

After reassembly, I tested the gun and found that it shot as normal... for about three cycles. The motor then proceed lock up again.

In my eight years of airsoft, I've never seen this before. What is up with my motor?

Stock G&P M120 motor? It seems to me that G&P motors have a tendency for their springs to pop out every once in a while. To fix it, will require disassembly of your motor to reset the spring where it should be. Either that, or a winding has come loose, and if that's the case, you'd be better off buying a new motor.

It's not a stock motor it's an Aim/Top m130 motor, and it's still relatively new. I don't really have experience disassembling motors themselves, how would you recommend doing that?

hmmm, well it seems that you may have gotten a dud motor. That also means it's more likely one of the windings has come lose, meaning the motor will need to be replaced or the armature (the part that spins) will need to be replaced.

Taking apart a motor is not an easy thing to do, the hardest part is taking the pinion gear off without damaging the gear, or the rest of the motor. The end bell is relatively easy to remove, but there are several different ways that it is attached to the motor. It's either got screws on the side, there are tabs that are bent in, holding it in place, or there are small screws on the top of the motor holding it down. You'll need to remove the screws or bend the tabs out to take the end bell off. I also suggest removing the brush springs and the brushes themselves so you don't scratch the armature. basically, you want to try to get a look inside the motor to see what is causing the hold up. If a spring has come lose, or it's a piece of dirt, it's somewhat fixable, otherwise it's more effort than it's worth to fix it.

Sounds like quite a hassle. I'll just swap out the motor with a lower power one for now, because I'm almost positive that I don't have anything that'll dislodge the pinion gear. I'll keep your advice in mind though once I get my hands on a gear puller or something of the like.

The best ones to get are the Element ones, but they will run you $30-$40 depending on where you find them.

If you cannot (without forcing it and hearing a scraping sound etc.) turn the pinion by hand, a peice of metal (possibly small screw) likely fell down inside the motor between the magnets on the outside and the commutator shaft in the center. I would replace the motor.

Ugh, this rifle is becoming a money pit.