I did some searching and didn't find anything quite like my problem so excuse me if the answer already here somewhere.
My friends warranty ran out a few days ago, so he asked me to teach him how to break his gun down and remove the mechbox if needed to for reapirs, etc. Well needless to say it was pretty simple. I showed him how to remove the gearbox (we never opened it at this point, just removed it from the receiver), and then reassembled everything. Once we got it back together we went outside to shoot, and it would not feed more than one or two bb's every time you started shooting. Full auto was the same, not wanting to feed at all. Before we took it apart, it pretty well with an awesome ROF. Maybe one or two misfeeds every 50 rounds.
I have double and triple checked to make sure a part was not left out. The hop-up is nice and springy, and meshes nicely when the gun is assembled.
So I start inspecting the magwell/hop-up area and it appears the air nozzle isn't stopping all the way back after each cycle like it should be. This seems to be preventing it from feeding anything into the hop-up. Upon further inspection I noticed if you fire enough shots, every once in a while the nozzle is all the way back. If you insert a mag at this point, it will feed and fire one shot perfectly, then will not feed any more.
My first thought was a tappet plate malfunction. Maybe stretched or cracked, causing the sector gear not to pull the nozzle back properly. So I opened the gearbox and inspected the tappet plate, along with the other internals. Everything looks perfect. I replaced the tappet plate just for good measure and it still has the same problem.
So now I am stumped. I am thinking maybe the lipo is just overspinning the gears too much and too fast to effeciently load bb's (I noticed the motor overspins a lot, causing the piston to almost always be half cocked), but it doesnt seem to make sense considering the gun was feeding well before disassembly.
Edited by KXR4, 14 March 2011 - 05:01 PM.