M4 v2 gearbox issue

[Sonkut]

Hey Guys,

Trying to get my M4 working so I can get back to airsoft after a break… mostly related to me insisting on having my M4 working.. It’s my main gun, I love it, and it’s never worked lol! It’s my first project gun, many parts, many manufacturers, making it a total Git! The one problem that I’ve never managed to fix is: after putting it back together, it get through about 10-30 rounds then jams.

This isn’t due to my battery, I’ve tried it with a 11.1 fully charged lipo. It seems like it’s too tight or the gears are rubbing, but I’ve changed the gears, re-shimmed it half a hundred times, I was even concerned it was the crappy gearbox from the original donor gun so I replaced it with a hardened hearbox. I found the gears rubbed in places with that so I filed it down in area’s. But it still jams with the piston pulled 95% back. Could it be the spring guide getting in the way? (it’s a bearing spring guide).

I honestly am stuck for idea’s, kinda makes everyone including me laugh as I’m the engineer for my particular group of friends, I can fix and upgrade almost anything they give me (aeg anyhow) but I can’t get my beloved M4 working! I’m at the point that I’m happy to send it off for someone else to look at as I’m fed up with it. Grrrrrr

Advice?

[mrpugster]

Re: M4 v2 gearbox issue

If you've got a spring guide without any bearings definitely worth a try. Also before you put the gearbox back into the body get a long screw driver and push the piston head all the way back and see if it catches.

[ElZer0]

Re: M4 v2 gearbox issue

Does the pistol grip/motor get warm/hot?

What grip a d motor are you using??

What Make is the m4 and gearbox?

I ask as my jg416 with a gp gear box used to have issues due to to it not liking the fb.

Also when you put the motor in, where do the wires go?

I've been told both wires need to run behind the motor in m4s

[Decho]

Re: M4 v2 gearbox issue

The wires can be anywhere, but normally with +ve in front and -ve behind, if I remember correctly. No idea what the OP's problem is, sorry.

[Sonkut]

Re: M4 v2 gearbox issue

Hey Guys,

Sorry not replied yet, been up to my ears in motorcycle but hey, i's working now XD

The gearbox is... well, there are a lot of different parts from different suppliers.The case is I think a G&P Hardened case, the piston and cylinder+head are systema teflon, the spring is.... uhh... from a classic army G63K originally i put in just in case the other spring was too strong.. The Spring guide i think was a random one from element, which also looks like it has a crack running down the side ... The gears i have two sets, neither seem to work, one is a 200% torq element gears one are a bunch of bog standard V2 gears I got from E-Bay, something like "SA" but can't remember.

The Motor is a CA High speed Motor housed in this grip. The possibility that the grip makes the motor not sit right has been considered, as well as positioning of the wires to make sure the motor is making good contact, but i couldn't get it to make the difference. I may have a bearing free spring guide but it's a horrible bit of crappy plastic from a cheap Chinese gearbox.

Thanks for your help guys.

[brewer17]

Re: M4 v2 gearbox issue

Sorry to thread jack but.....

My V2 gearbox has this problem. I can confirm that it was the spring guide that was causing the issue. As soon as I swapped it over for a different one. The gearbox works flawlessly.

[Sonkut]

Re: M4 v2 gearbox issue

@brewer17

If your right.... I think i'll love you forever.

I'm gona order a good spring guide.

[Sonkut]

Re: M4 v2 gearbox issue

Hey guys,

Just thought i would inform you that replacing the spring guide with a spare (crap one but hey) seems to have done the job, i think the bearing was getting in the way by the looks. Thanks for you help, the guns working now XD Just got to find a good spring guide now... next job is to sup up my mp5K!