I bought a Marui SG1 from a board member a while back (can't find the post for it anymore) that had been upgraded and I can't remember what the upgrades were. I used it a few times and it worked great but some time ago it stopped firing right and made nasty grinding sounds. I stopped using it after the grinding started to try and minimize any damage and got busy so it's been sitting in a closet for a long time. I finally got around to taking it apart today and found the bevel gear has a partially broken tooth, badly enough so the gears just bind at that point. Everything else looks good other than it needs grease. My question is if there is any way to get a new gear without having to get a whole set and a new spring to make sure it all matches. I know the spring was upgraded, but don't know of any way to find out what the spring actually is so I don't want to get a gear/gearset that won't do the job.
