M4 - Gears aren't turning, but I know the motor works

Discussion in 'Gun Building, Modifications & Repairs' started by guitarmaniak, Jul 27, 2012.

  1. guitarmaniak

    guitarmaniak New Member

    Ok, so I just took apart my gearbox to rewire it all to the front. I went ahead and shimmed a bit while I had it all opened up. Before I put the piston and all that in I closed up the gearbox and used my finger to move the gears to make sure they meshed good. They moved very smoothly, so I put everything back in and closed it up for good. After putting the motor/grip on I pulled the trigger and... nothing.:mad: I could very faintly hear the motor trying to turn and when I stuck my nose up to the bottom of the grip I could smell it a little. So I then took the motor out and just held it while I pulled the trigger; it whirred to life.

    I took the gearbox apart like 3 times to double check everything inside and I can't figure out what could be wrong. It seems like the only viable reason would be that the gears are somehow unable to spin, but like I said they spun just fine before I put the piston in.

    Any thoughts? I have my first game tomorrow so I'd really like to get this working. Lol.

  2. GreenListerine

    GreenListerine New Member

    What is your set up inside the gun? Are you sure the arl didn't pop out before you closed the gearbox? If you did any soldering, check the solder joints over again. Also, some guns have a silver disk in the pistol grip for the motor. Make sure you didn't lose that disk.

  3. Sparky_D

    Sparky_D Moderator Staff Member Moderator

    Pierce County
    Did you accidently reverse the polarity on the motor leads?

    Or is the motor adjustment too tight? I always start with my motor adjustment screw all the way out (motor whirrs without meshing with bevel), then tighten one full turn until engagement, then 1/4 turn until perfect height.
  4. guitarmaniak

    guitarmaniak New Member

    Hm.. I'm thinking the motor adjustment might be what's wrong. I know I had it screwed in all the way when I took it off. I'll try that.
  5. captain zacheus

    captain zacheus New Member

    I guarantee it's the motor height....I had the same problem a while back while fixing a friend's V2