5 replies to this topic

[Tronstamos]

I have a KWA M4 and the fuses started overheating and the gun would not fire. I took it to my local airsoft shop and asked them to fix it. When i got it back it started shooting well but at around 480 FPS I thought that that was a little wierd but thought nothing of it. Now instead of the fuses overheating the wires connecting to the fuse are heating with every trigger pull. I do not know if i should just get a new motor or new fuses or what but i just need to know the problem and how to fix it.

[optimuskmg]

you start by looking for any pinched wire's that could be causing a short in your electrical system

[aaps59]

Yep, have you done any work with your buffer tube or stock? Or your motor/pistol grip?

[niko_gpsy]

Wires becoming excessively hot after only a few shots is a sure indication that you have a pinch somewhere in the wiring.  The easiest place to check is the motor grip and buffer tube (if rear wired).  Look for flattened areas along the length of the wiring and be thorough.
Another area you may want to check are the connections like the tamiya (if you have not replaced them yet) and spade connectors that may have become loose. Also be sure that the motor terminal connectors are always securely connected since loose connection can also result in such symptom.
I have sometimes found that when working on guns that were previously opened by other techs is that the wiring coming out of the GB is pinched between the shell halves.  I would call this sloppy work but it can happen to the best of us sometimes.

[gcw360]

niko_gpsy, on 30 August 2012 - 04:07 AM, said:

Wires becoming excessively hot after only a few shots is a sure indication that you have a pinch somewhere in the wiring.  The easiest place to check is the motor grip and buffer tube (if rear wired).  Look for flattened areas along the length of the wiring and be thorough.
Another area you may want to check are the connections like the tamiya (if you have not replaced them yet) and spade connectors that may have become loose. Also be sure that the motor terminal connectors are always securely connected since loose connection can also result in such symptom.
I have sometimes found that when working on guns that were previously opened by other techs is that the wiring coming out of the GB is pinched between the shell halves.  I would call this sloppy work but it can happen to the best of us sometimes.

I'm with Niko.  The last two guns I found with pinched wires resulting in a short:

• Buffer tube at the lower receiver
  
• Between the two gearbox shell halves

[niko_gpsy]

Also make sure that the motor height isn't too high and if you shimmed the gears, make sure it isn't too tight and binding the gears. And sometimes the fuse can go bad and generate a lot of hear around that area but it can still work so have multiple 20A fuses to try.